diff --git a/src/boxerror.js b/src/boxerror.js
index d727611c0..9d32b6a3d 100644
--- a/src/boxerror.js
+++ b/src/boxerror.js
@@ -60,3 +60,9 @@ BoxError.UNKNOWN_ERROR = 'Unknown Error'; // only used for porting
 BoxError.prototype.toPlainObject = function () {
     return _.extend({}, { message: this.message, reason: this.reason }, this.details);
 };
+
+BoxError.prototype.setMessage = function (message) {
+    assert.strictEqual(typeof message, 'string');
+
+    this.message = message;
+};
\ No newline at end of file
diff --git a/src/ldap.js b/src/ldap.js
index c03ee4667..1d2747fa9 100644
--- a/src/ldap.js
+++ b/src/ldap.js
@@ -11,12 +11,10 @@ var assert = require('assert'),
     async = require('async'),
     constants = require('./constants.js'),
     BoxError = require('./boxerror.js'),
-    DatabaseError = require('./databaseerror.js'),
     debug = require('debug')('box:ldap'),
     eventlog = require('./eventlog.js'),
     ldap = require('ldapjs'),
     mail = require('./mail.js'),
-    MailError = mail.MailError,
     mailboxdb = require('./mailboxdb.js'),
     path = require('path'),
     safe = require('safetydance'),
@@ -262,7 +260,7 @@ function mailboxSearch(req, res, next) {
         if (parts.length !== 2) return next(new ldap.NoSuchObjectError(req.dn.toString()));
 
         mailboxdb.getMailbox(parts[0], parts[1], function (error, mailbox) {
-            if (error && error.reason === DatabaseError.NOT_FOUND) return next(new ldap.NoSuchObjectError(req.dn.toString()));
+            if (error && error.reason === BoxError.NOT_FOUND) return next(new ldap.NoSuchObjectError(req.dn.toString()));
             if (error) return next(new ldap.OperationsError(error.toString()));
 
             var obj = {
@@ -335,7 +333,7 @@ function mailAliasSearch(req, res, next) {
     if (parts.length !== 2) return next(new ldap.NoSuchObjectError(req.dn.toString()));
 
     mailboxdb.getAlias(parts[0], parts[1], function (error, alias) {
-        if (error && error.reason === DatabaseError.NOT_FOUND) return next(new ldap.NoSuchObjectError(req.dn.toString()));
+        if (error && error.reason === BoxError.NOT_FOUND) return next(new ldap.NoSuchObjectError(req.dn.toString()));
         if (error) return next(new ldap.OperationsError(error.toString()));
 
         // https://wiki.debian.org/LDAP/MigrationTools/Examples
@@ -373,7 +371,7 @@ function mailingListSearch(req, res, next) {
     if (parts.length !== 2) return next(new ldap.NoSuchObjectError(req.dn.toString()));
 
     mailboxdb.getList(parts[0], parts[1], function (error, list) {
-        if (error && error.reason === DatabaseError.NOT_FOUND) return next(new ldap.NoSuchObjectError(req.dn.toString()));
+        if (error && error.reason === BoxError.NOT_FOUND) return next(new ldap.NoSuchObjectError(req.dn.toString()));
         if (error) return next(new ldap.OperationsError(error.toString()));
 
         // http://ldapwiki.willeke.com/wiki/Original%20Mailgroup%20Schema%20From%20Netscape
@@ -458,13 +456,13 @@ function authenticateUserMailbox(req, res, next) {
     if (parts.length !== 2) return next(new ldap.NoSuchObjectError(req.dn.toString()));
 
     mail.getDomain(parts[1], function (error, domain) {
-        if (error && error.reason === MailError.NOT_FOUND) return next(new ldap.NoSuchObjectError(req.dn.toString()));
+        if (error && error.reason === BoxError.NOT_FOUND) return next(new ldap.NoSuchObjectError(req.dn.toString()));
         if (error) return next(new ldap.OperationsError(error.message));
 
         if (!domain.enabled) return next(new ldap.NoSuchObjectError(req.dn.toString()));
 
         mailboxdb.getMailbox(parts[0], parts[1], function (error, mailbox) {
-            if (error && error.reason === DatabaseError.NOT_FOUND) return next(new ldap.NoSuchObjectError(req.dn.toString()));
+            if (error && error.reason === BoxError.NOT_FOUND) return next(new ldap.NoSuchObjectError(req.dn.toString()));
             if (error) return next(new ldap.OperationsError(error.message));
 
             users.verify(mailbox.ownerId, req.credentials || '', function (error, result) {
@@ -556,7 +554,7 @@ function authenticateMailAddon(req, res, next) {
     const addonId = req.dn.rdns[1].attrs.ou.value.toLowerCase(); // 'sendmail' or 'recvmail'
 
     mail.getDomain(parts[1], function (error, domain) {
-        if (error && error.reason === MailError.NOT_FOUND) return next(new ldap.NoSuchObjectError(req.dn.toString()));
+        if (error && error.reason === BoxError.NOT_FOUND) return next(new ldap.NoSuchObjectError(req.dn.toString()));
         if (error) return next(new ldap.OperationsError(error.message));
 
         if (addonId === 'recvmail' && !domain.enabled) return next(new ldap.NoSuchObjectError(req.dn.toString()));
@@ -575,7 +573,7 @@ function authenticateMailAddon(req, res, next) {
             }
 
             mailboxdb.getMailbox(parts[0], parts[1], function (error, mailbox) {
-                if (error && error.reason === DatabaseError.NOT_FOUND) return next(new ldap.NoSuchObjectError(req.dn.toString()));
+                if (error && error.reason === BoxError.NOT_FOUND) return next(new ldap.NoSuchObjectError(req.dn.toString()));
                 if (error) return next(new ldap.OperationsError(error.message));
 
                 users.verify(mailbox.ownerId, req.credentials || '', function (error, result) {
diff --git a/src/mail.js b/src/mail.js
index e6cd76275..99c4842e9 100644
--- a/src/mail.js
+++ b/src/mail.js
@@ -46,15 +46,13 @@ exports = module.exports = {
     updateList: updateList,
     removeList: removeList,
 
-    _readDkimPublicKeySync: readDkimPublicKeySync,
-
-    MailError: MailError
+    _readDkimPublicKeySync: readDkimPublicKeySync
 };
 
 var assert = require('assert'),
     async = require('async'),
+    BoxError = require('./boxerror.js'),
     constants = require('./constants.js'),
-    DatabaseError = require('./databaseerror.js'),
     debug = require('debug')('box:mail'),
     dns = require('./native-dns.js'),
     domains = require('./domains.js'),
@@ -75,47 +73,20 @@ var assert = require('assert'),
     smtpTransport = require('nodemailer-smtp-transport'),
     sysinfo = require('./sysinfo.js'),
     users = require('./users.js'),
-    util = require('util'),
     validator = require('validator'),
     _ = require('underscore');
 
 const DNS_OPTIONS = { timeout: 5000 };
 var NOOP_CALLBACK = function (error) { if (error) debug(error); };
 
-function MailError(reason, errorOrMessage) {
-    assert.strictEqual(typeof reason, 'string');
-    assert(errorOrMessage instanceof Error || typeof errorOrMessage === 'string' || typeof errorOrMessage === 'undefined');
-
-    Error.call(this);
-    Error.captureStackTrace(this, this.constructor);
-
-    this.name = this.constructor.name;
-    this.reason = reason;
-    if (typeof errorOrMessage === 'undefined') {
-        this.message = reason;
-    } else if (typeof errorOrMessage === 'string') {
-        this.message = errorOrMessage;
-    } else {
-        this.message = 'Internal error';
-        this.nestedError = errorOrMessage;
-    }
-}
-util.inherits(MailError, Error);
-MailError.INTERNAL_ERROR = 'Internal Error';
-MailError.EXTERNAL_ERROR = 'External Error';
-MailError.BAD_FIELD = 'Bad Field';
-MailError.ALREADY_EXISTS = 'Already Exists';
-MailError.NOT_FOUND = 'Not Found';
-MailError.IN_USE = 'In Use';
-
 function validateName(name) {
     assert.strictEqual(typeof name, 'string');
 
-    if (name.length < 1) return new MailError(MailError.BAD_FIELD, 'mailbox name must be atleast 1 char');
-    if (name.length >= 200) return new MailError(MailError.BAD_FIELD, 'mailbox name too long');
+    if (name.length < 1) return new BoxError(BoxError.BAD_FIELD, 'mailbox name must be atleast 1 char');
+    if (name.length >= 200) return new BoxError(BoxError.BAD_FIELD, 'mailbox name too long');
 
     // also need to consider valid LDAP characters here (e.g '+' is reserved)
-    if (/[^a-zA-Z0-9.-]/.test(name)) return new MailError(MailError.BAD_FIELD, 'mailbox name can only contain alphanumerals and dot');
+    if (/[^a-zA-Z0-9.-]/.test(name)) return new BoxError(BoxError.BAD_FIELD, 'mailbox name can only contain alphanumerals and dot');
 
     return null;
 }
@@ -204,7 +175,7 @@ function verifyRelay(relay, callback) {
     if (relay.provider === 'cloudron-smtp' || relay.provider === 'noop') return callback();
 
     checkSmtpRelay(relay, function (error) {
-        if (error) return callback(new MailError(MailError.BAD_FIELD, error.message));
+        if (error) return callback(new BoxError(BoxError.BAD_FIELD, error.message));
 
         callback();
     });
@@ -701,7 +672,8 @@ function restartMailIfActivated(callback) {
     assert.strictEqual(typeof callback, 'function');
 
     users.isActivated(function (error, activated) {
-        if (error) return callback(new MailError(MailError.INTERNAL_ERROR, error));
+        if (error) return callback(error);
+
         if (!activated) {
             debug('restartMailIfActivated: skipping restart of mail container since Cloudron is not activated yet');
             return callback(); // not provisioned yet, do not restart container after dns setup
@@ -723,8 +695,7 @@ function getDomain(domain, callback) {
     assert.strictEqual(typeof callback, 'function');
 
     maildb.get(domain, function (error, result) {
-        if (error && error.reason === DatabaseError.NOT_FOUND) return callback(new MailError(MailError.NOT_FOUND));
-        if (error) return callback(new MailError(MailError.INTERNAL_ERROR, error));
+        if (error) return callback(error);
 
         return callback(null, result);
     });
@@ -734,7 +705,7 @@ function getDomains(callback) {
     assert.strictEqual(typeof callback, 'function');
 
     maildb.list(function (error, results) {
-        if (error) return callback(new MailError(MailError.INTERNAL_ERROR, error));
+        if (error) return callback(error);
 
         return callback(null, results);
     });
@@ -747,7 +718,7 @@ function txtRecordsWithSpf(domain, mailFqdn, callback) {
     assert.strictEqual(typeof callback, 'function');
 
     domains.getDnsRecords('', domain, 'TXT', function (error, txtRecords) {
-        if (error) return new MailError(MailError.EXTERNAL_ERROR, error.message);
+        if (error) return error;
 
         debug('txtRecordsWithSpf: current txt records - %j', txtRecords);
 
@@ -796,16 +767,16 @@ function ensureDkimKeySync(mailDomain) {
 
     if (!safe.fs.mkdirSync(dkimPath) && safe.error.code !== 'EEXIST') {
         debug('Error creating dkim.', safe.error);
-        return new MailError(MailError.INTERNAL_ERROR, safe.error);
+        return new BoxError(BoxError.FS_ERROR, safe.error);
     }
 
-    if (!safe.child_process.execSync('openssl genrsa -out ' + dkimPrivateKeyFile + ' 1024')) return new MailError(MailError.INTERNAL_ERROR, safe.error);
-    if (!safe.child_process.execSync('openssl rsa -in ' + dkimPrivateKeyFile + ' -out ' + dkimPublicKeyFile + ' -pubout -outform PEM')) return new MailError(MailError.INTERNAL_ERROR, safe.error);
+    if (!safe.child_process.execSync('openssl genrsa -out ' + dkimPrivateKeyFile + ' 1024')) return new BoxError(BoxError.OPENSSL_ERROR, safe.error);
+    if (!safe.child_process.execSync('openssl rsa -in ' + dkimPrivateKeyFile + ' -out ' + dkimPublicKeyFile + ' -pubout -outform PEM')) return new BoxError(BoxError.OPENSSL_ERROR, safe.error);
 
-    if (!safe.fs.writeFileSync(dkimSelectorFile, mailDomain.dkimSelector, 'utf8')) return new MailError(MailError.INTERNAL_ERROR, safe.error);
+    if (!safe.fs.writeFileSync(dkimSelectorFile, mailDomain.dkimSelector, 'utf8')) return new BoxError(BoxError.FS_ERROR, safe.error);
 
     // if the 'yellowtent' user of OS and the 'cloudron' user of mail container don't match, the keys become inaccessible by mail code
-    if (!safe.fs.chmodSync(dkimPrivateKeyFile, 0o644)) return new MailError(MailError.INTERNAL_ERROR, safe.error);
+    if (!safe.fs.chmodSync(dkimPrivateKeyFile, 0o644)) return new BoxError(BoxError.FS_ERROR, safe.error);
 
     return null;
 }
@@ -837,8 +808,7 @@ function upsertDnsRecords(domain, mailFqdn, callback) {
     debug(`upsertDnsRecords: updating mail dns records of domain ${domain} and mail fqdn ${mailFqdn}`);
 
     maildb.get(domain, function (error, mailDomain) {
-        if (error && error.reason === DatabaseError.NOT_FOUND) return callback(new MailError(MailError.NOT_FOUND));
-        if (error) return callback(new MailError(MailError.INTERNAL_ERROR, error));
+        if (error) return callback(error);
 
         error = ensureDkimKeySync(mailDomain);
         if (error) return callback(error);
@@ -846,7 +816,7 @@ function upsertDnsRecords(domain, mailFqdn, callback) {
         if (process.env.BOX_ENV === 'test') return callback();
 
         var dkimKey = readDkimPublicKeySync(domain);
-        if (!dkimKey) return callback(new MailError(MailError.INTERNAL_ERROR, new Error('Failed to read dkim public key')));
+        if (!dkimKey) return callback(new BoxError(BoxError.FS_ERROR, new Error('Failed to read dkim public key')));
 
         // t=s limits the domainkey to this domain and not it's subdomains
         var dkimRecord = { subdomain: `${mailDomain.dkimSelector}._domainkey`, domain: domain, type: 'TXT', values: [ '"v=DKIM1; t=s; p=' + dkimKey + '"' ] };
@@ -870,7 +840,7 @@ function upsertDnsRecords(domain, mailFqdn, callback) {
             }, function (error, changeIds) {
                 if (error) {
                     debug(`upsertDnsRecords: failed to update: ${error}`);
-                    return callback(new MailError(MailError.EXTERNAL_ERROR, error.message));
+                    return callback(error);
                 }
 
                 debug('upsertDnsRecords: records %j added with changeIds %j', records, changeIds);
@@ -895,12 +865,12 @@ function onMailFqdnChanged(callback) {
         mailDomain = settings.adminDomain();
 
     domains.getAll(function (error, allDomains) {
-        if (error) return callback(new MailError(MailError.INTERNAL_ERROR, error));
+        if (error) return callback(error.setMessage('Error getting domains'));
 
         async.eachOfSeries(allDomains, function (domainObject, idx, iteratorDone) {
             upsertDnsRecords(domainObject.domain, mailFqdn, iteratorDone);
         }, function (error) {
-            if (error) return callback(new MailError(MailError.EXTERNAL_ERROR, error.message));
+            if (error) return callback(error);
 
             configureMail(mailFqdn, mailDomain, callback);
         });
@@ -914,9 +884,7 @@ function addDomain(domain, callback) {
     const dkimSelector = domain === settings.adminDomain() ? 'cloudron' : ('cloudron-' + settings.adminDomain().replace(/\./g, ''));
 
     maildb.add(domain, { dkimSelector }, function (error) {
-        if (error && error.reason === DatabaseError.ALREADY_EXISTS) return callback(new MailError(MailError.ALREADY_EXISTS, 'Domain already exists'));
-        if (error && error.reason === DatabaseError.NOT_FOUND) return callback(new MailError(MailError.NOT_FOUND, 'No such domain'));
-        if (error) return callback(new MailError(MailError.INTERNAL_ERROR, error));
+        if (error) return callback(error);
 
         async.series([
             upsertDnsRecords.bind(null, domain, settings.mailFqdn()), // do this first to ensure DKIM keys
@@ -931,12 +899,10 @@ function removeDomain(domain, callback) {
     assert.strictEqual(typeof domain, 'string');
     assert.strictEqual(typeof callback, 'function');
 
-    if (domain === settings.adminDomain()) return callback(new MailError(MailError.IN_USE));
+    if (domain === settings.adminDomain()) return callback(new BoxError(BoxError.CONFLICT));
 
     maildb.del(domain, function (error) {
-        if (error && error.reason === DatabaseError.IN_USE) return callback(new MailError(MailError.IN_USE));
-        if (error && error.reason === DatabaseError.NOT_FOUND) return callback(new MailError(MailError.NOT_FOUND, error.message));
-        if (error) return callback(new MailError(MailError.INTERNAL_ERROR, error));
+        if (error) return callback(error);
 
         restartMail(NOOP_CALLBACK);
 
@@ -948,7 +914,7 @@ function clearDomains(callback) {
     assert.strictEqual(typeof callback, 'function');
 
     maildb.clear(function (error) {
-        if (error) return callback(new MailError(MailError.INTERNAL_ERROR, error));
+        if (error) return callback(error);
 
         callback();
     });
@@ -970,8 +936,7 @@ function setMailFromValidation(domain, enabled, callback) {
     assert.strictEqual(typeof callback, 'function');
 
     maildb.update(domain, { mailFromValidation: enabled }, function (error) {
-        if (error && error.reason === DatabaseError.NOT_FOUND) return callback(new MailError(MailError.NOT_FOUND));
-        if (error) return callback(new MailError(MailError.INTERNAL_ERROR, error));
+        if (error) return callback(error);
 
         restartMail(NOOP_CALLBACK); // have to restart mail container since haraka cannot watch symlinked config files (mail.ini)
 
@@ -985,8 +950,7 @@ function setCatchAllAddress(domain, addresses, callback) {
     assert.strictEqual(typeof callback, 'function');
 
     maildb.update(domain, { catchAll: addresses }, function (error) {
-        if (error && error.reason === DatabaseError.NOT_FOUND) return callback(new MailError(MailError.NOT_FOUND));
-        if (error) return callback(new MailError(MailError.INTERNAL_ERROR, error));
+        if (error) return callback(error);
 
         restartMail(NOOP_CALLBACK); // have to restart mail container since haraka cannot watch symlinked config files (mail.ini)
 
@@ -1012,8 +976,7 @@ function setMailRelay(domain, relay, callback) {
             if (error) return callback(error);
 
             maildb.update(domain, { relay: relay }, function (error) {
-                if (error && error.reason === DatabaseError.NOT_FOUND) return callback(new MailError(MailError.NOT_FOUND));
-                if (error) return callback(new MailError(MailError.INTERNAL_ERROR, error));
+                if (error) return callback(error);
 
                 restartMail(NOOP_CALLBACK);
 
@@ -1030,8 +993,7 @@ function setMailEnabled(domain, enabled, auditSource, callback) {
     assert.strictEqual(typeof callback, 'function');
 
     maildb.update(domain, { enabled: enabled }, function (error) {
-        if (error && error.reason === DatabaseError.NOT_FOUND) return callback(new MailError(MailError.NOT_FOUND));
-        if (error) return callback(new MailError(MailError.INTERNAL_ERROR, error));
+        if (error) return callback(error);
 
         restartMail(NOOP_CALLBACK);
 
@@ -1050,7 +1012,7 @@ function sendTestMail(domain, to, callback) {
         if (error) return callback(error);
 
         mailer.sendTestMail(result.domain, to, function (error) {
-            if (error) return callback(new MailError(MailError.EXTERNAL_ERROR, error.message));
+            if (error) return callback(error);
 
             callback();
         });
@@ -1064,7 +1026,7 @@ function listMailboxes(domain, page, perPage, callback) {
     assert.strictEqual(typeof callback, 'function');
 
     mailboxdb.listMailboxes(domain, page, perPage, function (error, result) {
-        if (error) return callback(new MailError(MailError.INTERNAL_ERROR, error));
+        if (error) return callback(error);
 
         callback(null, result);
     });
@@ -1075,7 +1037,7 @@ function removeMailboxes(domain, callback) {
     assert.strictEqual(typeof callback, 'function');
 
     mailboxdb.delByDomain(domain, function (error) {
-        if (error) return callback(new MailError(MailError.INTERNAL_ERROR, error));
+        if (error) return callback(error);
 
         callback();
     });
@@ -1087,8 +1049,7 @@ function getMailbox(name, domain, callback) {
     assert.strictEqual(typeof callback, 'function');
 
     mailboxdb.getMailbox(name, domain, function (error, result) {
-        if (error && error.reason === DatabaseError.NOT_FOUND) return callback(new MailError(MailError.NOT_FOUND, 'no such mailbox'));
-        if (error) return callback(new MailError(MailError.INTERNAL_ERROR, error));
+        if (error) return callback(error);
 
         callback(null, result);
     });
@@ -1107,8 +1068,7 @@ function addMailbox(name, domain, userId, auditSource, callback) {
     if (error) return callback(error);
 
     mailboxdb.addMailbox(name, domain, userId, function (error) {
-        if (error && error.reason === DatabaseError.ALREADY_EXISTS) return callback(new MailError(MailError.ALREADY_EXISTS, `mailbox ${name} already exists`));
-        if (error) return callback(new MailError(MailError.INTERNAL_ERROR, error));
+        if (error) return callback(error);
 
         eventlog.add(eventlog.ACTION_MAIL_MAILBOX_ADD, auditSource, { name, domain, userId });
 
@@ -1125,8 +1085,7 @@ function updateMailboxOwner(name, domain, userId, callback) {
     name = name.toLowerCase();
 
     mailboxdb.updateMailboxOwner(name, domain, userId, function (error) {
-        if (error && error.reason === DatabaseError.NOT_FOUND) return callback(new MailError(MailError.NOT_FOUND, 'no such mailbox'));
-        if (error) return callback(new MailError(MailError.INTERNAL_ERROR, error));
+        if (error) return callback(error);
 
         callback(null);
     });
@@ -1139,8 +1098,7 @@ function removeMailbox(name, domain, auditSource, callback) {
     assert.strictEqual(typeof callback, 'function');
 
     mailboxdb.del(name, domain, function (error) {
-        if (error && error.reason === DatabaseError.NOT_FOUND) return callback(new MailError(MailError.NOT_FOUND, 'no such mailbox'));
-        if (error) return callback(new MailError(MailError.INTERNAL_ERROR, error));
+        if (error) return callback(error);
 
         eventlog.add(eventlog.ACTION_MAIL_MAILBOX_REMOVE, auditSource, { name, domain });
 
@@ -1155,8 +1113,7 @@ function listAliases(domain, page, perPage, callback) {
     assert.strictEqual(typeof callback, 'function');
 
     mailboxdb.listAliases(domain, page, perPage, function (error, result) {
-        if (error && error.reason === DatabaseError.NOT_FOUND) return callback(new MailError(MailError.NOT_FOUND, error.message));
-        if (error) return callback(new MailError(MailError.INTERNAL_ERROR, error));
+        if (error) return callback(error);
 
         callback(null, result);
     });
@@ -1171,8 +1128,7 @@ function getAliases(name, domain, callback) {
         if (error) return callback(error);
 
         mailboxdb.getAliasesForName(name, domain, function (error, aliases) {
-            if (error && error.reason === DatabaseError.NOT_FOUND) return callback(new MailError(MailError.NOT_FOUND, 'no such mailbox'));
-            if (error) return callback(new MailError(MailError.INTERNAL_ERROR, error));
+            if (error) return callback(error);
 
             callback(null, aliases);
         });
@@ -1193,14 +1149,12 @@ function setAliases(name, domain, aliases, callback) {
     }
 
     mailboxdb.setAliasesForName(name, domain, aliases, function (error) {
-        if (error && error.reason === DatabaseError.ALREADY_EXISTS && error.message.indexOf('mailboxes_name_domain_unique_index') !== -1) {
+        if (error && error.reason === BoxError.ALREADY_EXISTS && error.message.indexOf('mailboxes_name_domain_unique_index') !== -1) {
             var aliasMatch = error.message.match(new RegExp(`^ER_DUP_ENTRY: Duplicate entry '(.*)-${domain}' for key 'mailboxes_name_domain_unique_index'$`));
-            if (!aliasMatch) return callback(new MailError(MailError.ALREADY_EXISTS, error.message));
-            return callback(new MailError(MailError.ALREADY_EXISTS, `Mailbox, mailinglist or alias for ${aliasMatch[1]} already exists`));
+            if (!aliasMatch) return callback(error);
+            return callback(error.setMessage(`Mailbox, mailinglist or alias for ${aliasMatch[1]} already exists`));
         }
-        if (error && error.reason === DatabaseError.ALREADY_EXISTS) return callback(new MailError(MailError.ALREADY_EXISTS, error.message));
-        if (error && error.reason === DatabaseError.NOT_FOUND) return callback(new MailError(MailError.NOT_FOUND, 'no such mailbox'));
-        if (error) return callback(new MailError(MailError.INTERNAL_ERROR, error));
+        if (error) return callback(error);
 
         callback(null);
     });
@@ -1211,7 +1165,7 @@ function getLists(domain, callback) {
     assert.strictEqual(typeof callback, 'function');
 
     mailboxdb.getLists(domain, function (error, result) {
-        if (error) return callback(new MailError(MailError.INTERNAL_ERROR, error));
+        if (error) return callback(error);
 
         callback(null, result);
     });
@@ -1223,8 +1177,7 @@ function getList(domain, listName, callback) {
     assert.strictEqual(typeof callback, 'function');
 
     mailboxdb.getList(listName, domain, function (error, result) {
-        if (error && error.reason === DatabaseError.NOT_FOUND) return callback(new MailError(MailError.NOT_FOUND, 'no such list'));
-        if (error) return callback(new MailError(MailError.INTERNAL_ERROR, error));
+        if (error) return callback(error);
 
         callback(null, result);
     });
@@ -1243,12 +1196,11 @@ function addList(name, domain, members, auditSource, callback) {
     if (error) return callback(error);
 
     for (var i = 0; i < members.length; i++) {
-        if (!validator.isEmail(members[i])) return callback(new MailError(MailError.BAD_FIELD, 'Invalid mail member: ' + members[i]));
+        if (!validator.isEmail(members[i])) return callback(new BoxError(BoxError.BAD_FIELD, 'Invalid mail member: ' + members[i]));
     }
 
     mailboxdb.addList(name, domain, members, function (error) {
-        if (error && error.reason === DatabaseError.ALREADY_EXISTS) return callback(new MailError(MailError.ALREADY_EXISTS, 'list already exits'));
-        if (error) return callback(new MailError(MailError.INTERNAL_ERROR, error));
+        if (error) return callback(error);
 
         eventlog.add(eventlog.ACTION_MAIL_LIST_ADD, auditSource, { name, domain });
 
@@ -1268,12 +1220,11 @@ function updateList(name, domain, members, callback) {
     if (error) return callback(error);
 
     for (var i = 0; i < members.length; i++) {
-        if (!validator.isEmail(members[i])) return callback(new MailError(MailError.BAD_FIELD, 'Invalid email: ' + members[i]));
+        if (!validator.isEmail(members[i])) return callback(new BoxError(BoxError.BAD_FIELD, 'Invalid email: ' + members[i]));
     }
 
     mailboxdb.updateList(name, domain, members, function (error) {
-        if (error && error.reason === DatabaseError.NOT_FOUND) return callback(new MailError(MailError.NOT_FOUND, 'no such mailbox'));
-        if (error) return callback(new MailError(MailError.INTERNAL_ERROR, error));
+        if (error) return callback(error);
 
         callback(null);
     });
@@ -1286,8 +1237,7 @@ function removeList(name, domain, auditSource, callback) {
     assert.strictEqual(typeof callback, 'function');
 
     mailboxdb.del(name, domain, function (error) {
-        if (error && error.reason === DatabaseError.NOT_FOUND) return callback(new MailError(MailError.NOT_FOUND, 'no such list'));
-        if (error) return callback(new MailError(MailError.INTERNAL_ERROR, error));
+        if (error) return callback(error);
 
         eventlog.add(eventlog.ACTION_MAIL_LIST_ADD, auditSource, { name, domain });
 
diff --git a/src/mailboxdb.js b/src/mailboxdb.js
index d5952686a..4d22f76b9 100644
--- a/src/mailboxdb.js
+++ b/src/mailboxdb.js
@@ -33,8 +33,8 @@ exports = module.exports = {
 };
 
 var assert = require('assert'),
+    BoxError = require('./boxerror.js'),
     database = require('./database.js'),
-    DatabaseError = require('./databaseerror.js'),
     safe = require('safetydance'),
     util = require('util');
 
@@ -54,8 +54,8 @@ function addMailbox(name, domain, ownerId, callback) {
     assert.strictEqual(typeof callback, 'function');
 
     database.query('INSERT INTO mailboxes (name, type, domain, ownerId) VALUES (?, ?, ?, ?)', [ name, exports.TYPE_MAILBOX, domain, ownerId ], function (error) {
-        if (error && error.code === 'ER_DUP_ENTRY') return callback(new DatabaseError(DatabaseError.ALREADY_EXISTS, 'mailbox already exists'));
-        if (error) return callback(new DatabaseError(DatabaseError.INTERNAL_ERROR, error));
+        if (error && error.code === 'ER_DUP_ENTRY') return callback(new BoxError(BoxError.ALREADY_EXISTS, 'mailbox already exists'));
+        if (error) return callback(new BoxError(BoxError.DATABASE_ERROR, error));
 
         callback(null);
     });
@@ -68,8 +68,8 @@ function updateMailboxOwner(name, domain, ownerId, callback) {
     assert.strictEqual(typeof callback, 'function');
 
     database.query('UPDATE mailboxes SET ownerId = ? WHERE name = ? AND domain = ?', [ ownerId, name, domain ], function (error, result) {
-        if (error) return callback(new DatabaseError(DatabaseError.INTERNAL_ERROR, error));
-        if (result.affectedRows === 0) return callback(new DatabaseError(DatabaseError.NOT_FOUND));
+        if (error) return callback(new BoxError(BoxError.DATABASE_ERROR, error));
+        if (result.affectedRows === 0) return callback(new BoxError(BoxError.NOT_FOUND));
 
         callback(null);
     });
@@ -83,8 +83,8 @@ function addList(name, domain, members, callback) {
 
     database.query('INSERT INTO mailboxes (name, type, domain, ownerId, membersJson) VALUES (?, ?, ?, ?, ?)',
         [ name, exports.TYPE_LIST, domain, 'admin', JSON.stringify(members) ], function (error) {
-            if (error && error.code === 'ER_DUP_ENTRY') return callback(new DatabaseError(DatabaseError.ALREADY_EXISTS, 'mailbox already exists'));
-            if (error) return callback(new DatabaseError(DatabaseError.INTERNAL_ERROR, error));
+            if (error && error.code === 'ER_DUP_ENTRY') return callback(new BoxError(BoxError.ALREADY_EXISTS, 'mailbox already exists'));
+            if (error) return callback(new BoxError(BoxError.DATABASE_ERROR, error));
 
             callback(null);
         });
@@ -98,8 +98,8 @@ function updateList(name, domain, members, callback) {
 
     database.query('UPDATE mailboxes SET membersJson = ? WHERE name = ? AND domain = ?',
         [ JSON.stringify(members), name, domain ], function (error, result) {
-            if (error) return callback(new DatabaseError(DatabaseError.INTERNAL_ERROR, error));
-            if (result.affectedRows === 0) return callback(new DatabaseError(DatabaseError.NOT_FOUND));
+            if (error) return callback(new BoxError(BoxError.DATABASE_ERROR, error));
+            if (result.affectedRows === 0) return callback(new BoxError(BoxError.NOT_FOUND));
 
             callback(null);
         });
@@ -109,7 +109,7 @@ function clear(callback) {
     assert.strictEqual(typeof callback, 'function');
 
     database.query('TRUNCATE TABLE mailboxes', [], function (error) {
-        if (error) return callback(new DatabaseError(DatabaseError.INTERNAL_ERROR, error));
+        if (error) return callback(new BoxError(BoxError.DATABASE_ERROR, error));
         callback(null);
     });
 }
@@ -121,8 +121,8 @@ function del(name, domain, callback) {
 
     // deletes aliases as well
     database.query('DELETE FROM mailboxes WHERE (name=? OR aliasTarget = ?) AND domain = ?', [ name, name, domain ], function (error, result) {
-        if (error) return callback(new DatabaseError(DatabaseError.INTERNAL_ERROR, error));
-        if (result.affectedRows === 0) return callback(new DatabaseError(DatabaseError.NOT_FOUND));
+        if (error) return callback(new BoxError(BoxError.DATABASE_ERROR, error));
+        if (result.affectedRows === 0) return callback(new BoxError(BoxError.NOT_FOUND));
 
         callback(null);
     });
@@ -133,7 +133,7 @@ function delByDomain(domain, callback) {
     assert.strictEqual(typeof callback, 'function');
 
     database.query('DELETE FROM mailboxes WHERE domain = ?', [ domain ], function (error) {
-        if (error) return callback(new DatabaseError(DatabaseError.INTERNAL_ERROR, error));
+        if (error) return callback(new BoxError(BoxError.DATABASE_ERROR, error));
 
         callback(null);
     });
@@ -144,7 +144,7 @@ function delByOwnerId(id, callback) {
     assert.strictEqual(typeof callback, 'function');
 
     database.query('DELETE FROM mailboxes WHERE ownerId=?', [ id ], function (error) {
-        if (error) return callback(new DatabaseError(DatabaseError.INTERNAL_ERROR, error));
+        if (error) return callback(new BoxError(BoxError.DATABASE_ERROR, error));
 
         callback(null);
     });
@@ -161,9 +161,9 @@ function updateName(oldName, oldDomain, newName, newDomain, callback) {
     if (oldName === newName && oldDomain === newDomain) return callback(null);
 
     database.query('UPDATE mailboxes SET name=?, domain=? WHERE name=? AND domain = ?', [ newName, newDomain, oldName, oldDomain ], function (error, result) {
-        if (error && error.code === 'ER_DUP_ENTRY') return callback(new DatabaseError(DatabaseError.ALREADY_EXISTS, 'mailbox already exists'));
-        if (error) return callback(new DatabaseError(DatabaseError.INTERNAL_ERROR, error));
-        if (result.affectedRows !== 1) return callback(new DatabaseError(DatabaseError.NOT_FOUND));
+        if (error && error.code === 'ER_DUP_ENTRY') return callback(new BoxError(BoxError.ALREADY_EXISTS, 'mailbox already exists'));
+        if (error) return callback(new BoxError(BoxError.DATABASE_ERROR, error));
+        if (result.affectedRows !== 1) return callback(new BoxError(BoxError.NOT_FOUND));
 
         callback(null);
     });
@@ -176,8 +176,8 @@ function getMailbox(name, domain, callback) {
 
     database.query('SELECT ' + MAILBOX_FIELDS + ' FROM mailboxes WHERE name = ? AND type = ? AND domain = ?',
         [ name, exports.TYPE_MAILBOX, domain ], function (error, results) {
-            if (error) return callback(new DatabaseError(DatabaseError.INTERNAL_ERROR, error));
-            if (results.length === 0) return callback(new DatabaseError(DatabaseError.NOT_FOUND));
+            if (error) return callback(new BoxError(BoxError.DATABASE_ERROR, error));
+            if (results.length === 0) return callback(new BoxError(BoxError.NOT_FOUND));
 
             callback(null, postProcess(results[0]));
         });
@@ -191,7 +191,7 @@ function listMailboxes(domain, page, perPage, callback) {
 
     database.query(`SELECT ${MAILBOX_FIELDS} FROM mailboxes WHERE type = ? AND domain = ? ORDER BY name LIMIT ${(page-1)*perPage},${perPage}`,
         [ exports.TYPE_MAILBOX, domain ], function (error, results) {
-            if (error) return callback(new DatabaseError(DatabaseError.INTERNAL_ERROR, error));
+            if (error) return callback(new BoxError(BoxError.DATABASE_ERROR, error));
 
             results.forEach(function (result) { postProcess(result); });
 
@@ -205,7 +205,7 @@ function getLists(domain, callback) {
 
     database.query('SELECT ' + MAILBOX_FIELDS + ' FROM mailboxes WHERE type = ? AND domain = ?',
         [ exports.TYPE_LIST, domain ], function (error, results) {
-            if (error) return callback(new DatabaseError(DatabaseError.INTERNAL_ERROR, error));
+            if (error) return callback(new BoxError(BoxError.DATABASE_ERROR, error));
 
             results.forEach(function (result) { postProcess(result); });
 
@@ -220,8 +220,8 @@ function getList(name, domain, callback) {
 
     database.query('SELECT ' + MAILBOX_FIELDS + ' FROM mailboxes WHERE type = ? AND name = ? AND domain = ?',
         [ exports.TYPE_LIST, name, domain ], function (error, results) {
-            if (error) return callback(new DatabaseError(DatabaseError.INTERNAL_ERROR, error));
-            if (results.length === 0) return callback(new DatabaseError(DatabaseError.NOT_FOUND));
+            if (error) return callback(new BoxError(BoxError.DATABASE_ERROR, error));
+            if (results.length === 0) return callback(new BoxError(BoxError.NOT_FOUND));
 
             callback(null, postProcess(results[0]));
         });
@@ -232,8 +232,8 @@ function getByOwnerId(ownerId, callback) {
     assert.strictEqual(typeof callback, 'function');
 
     database.query('SELECT ' + MAILBOX_FIELDS + ' FROM mailboxes WHERE ownerId = ? ORDER BY name', [ ownerId ], function (error, results) {
-        if (error) return callback(new DatabaseError(DatabaseError.INTERNAL_ERROR, error));
-        if (results.length === 0) return callback(new DatabaseError(DatabaseError.NOT_FOUND));
+        if (error) return callback(new BoxError(BoxError.DATABASE_ERROR, error));
+        if (results.length === 0) return callback(new BoxError(BoxError.NOT_FOUND));
 
         results.forEach(function (result) { postProcess(result); });
 
@@ -248,8 +248,8 @@ function setAliasesForName(name, domain, aliases, callback) {
     assert.strictEqual(typeof callback, 'function');
 
     database.query('SELECT ' + MAILBOX_FIELDS + ' FROM mailboxes WHERE name = ? AND domain = ?', [ name, domain ], function (error, results) {
-        if (error) return callback(new DatabaseError(DatabaseError.INTERNAL_ERROR, error));
-        if (results.length === 0) return callback(new DatabaseError(DatabaseError.NOT_FOUND));
+        if (error) return callback(new BoxError(BoxError.DATABASE_ERROR, error));
+        if (results.length === 0) return callback(new BoxError(BoxError.NOT_FOUND));
 
         var queries = [];
         // clear existing aliases
@@ -260,8 +260,8 @@ function setAliasesForName(name, domain, aliases, callback) {
         });
 
         database.transaction(queries, function (error) {
-            if (error && error.code === 'ER_DUP_ENTRY') return callback(new DatabaseError(DatabaseError.ALREADY_EXISTS, error.message));
-            if (error) return callback(new DatabaseError(DatabaseError.INTERNAL_ERROR, error));
+            if (error && error.code === 'ER_DUP_ENTRY') return callback(new BoxError(BoxError.ALREADY_EXISTS, error.message));
+            if (error) return callback(new BoxError(BoxError.DATABASE_ERROR, error));
 
             callback(null);
         });
@@ -275,7 +275,7 @@ function getAliasesForName(name, domain, callback) {
 
     database.query('SELECT name FROM mailboxes WHERE type = ? AND aliasTarget = ? AND domain = ? ORDER BY name',
         [ exports.TYPE_ALIAS, name, domain ], function (error, results) {
-            if (error) return callback(new DatabaseError(DatabaseError.INTERNAL_ERROR, error));
+            if (error) return callback(new BoxError(BoxError.DATABASE_ERROR, error));
 
             results = results.map(function (r) { return r.name; });
             callback(null, results);
@@ -290,7 +290,7 @@ function listAliases(domain, page, perPage, callback) {
 
     database.query(`SELECT ${MAILBOX_FIELDS} FROM mailboxes WHERE domain = ? AND type = ? ORDER BY name LIMIT ${(page-1)*perPage},${perPage}`,
         [ domain, exports.TYPE_ALIAS ], function (error, results) {
-            if (error) return callback(new DatabaseError(DatabaseError.INTERNAL_ERROR, error));
+            if (error) return callback(new BoxError(BoxError.DATABASE_ERROR, error));
 
             results.forEach(function (result) { postProcess(result); });
 
@@ -305,8 +305,8 @@ function getAlias(name, domain, callback) {
 
     database.query('SELECT ' + MAILBOX_FIELDS + ' FROM mailboxes WHERE name = ? AND type = ? AND domain = ?',
         [ name, exports.TYPE_ALIAS, domain ], function (error, results) {
-            if (error) return callback(new DatabaseError(DatabaseError.INTERNAL_ERROR, error));
-            if (results.length === 0) return callback(new DatabaseError(DatabaseError.NOT_FOUND));
+            if (error) return callback(new BoxError(BoxError.DATABASE_ERROR, error));
+            if (results.length === 0) return callback(new BoxError(BoxError.NOT_FOUND));
 
             results.forEach(function (result) { postProcess(result); });
 
diff --git a/src/maildb.js b/src/maildb.js
index 8e21695a1..b7c516f49 100644
--- a/src/maildb.js
+++ b/src/maildb.js
@@ -15,8 +15,8 @@ exports = module.exports = {
 };
 
 var assert = require('assert'),
+    BoxError = require('./boxerror.js'),
     database = require('./database.js'),
-    DatabaseError = require('./databaseerror.js'),
     safe = require('safetydance');
 
 var MAILDB_FIELDS = [ 'domain', 'enabled', 'mailFromValidation', 'catchAllJson', 'relayJson', 'dkimSelector' ].join(',');
@@ -40,9 +40,9 @@ function add(domain, data, callback) {
     assert.strictEqual(typeof callback, 'function');
 
     database.query('INSERT INTO mail (domain, dkimSelector) VALUES (?, ?)', [ domain, data.dkimSelector || 'cloudron' ], function (error) {
-        if (error && error.code === 'ER_DUP_ENTRY') return callback(new DatabaseError(DatabaseError.ALREADY_EXISTS, 'mail domain already exists'));
-        if (error && error.code === 'ER_NO_REFERENCED_ROW_2') return callback(new DatabaseError(DatabaseError.NOT_FOUND), 'no such domain');
-        if (error) return callback(new DatabaseError(DatabaseError.INTERNAL_ERROR, error));
+        if (error && error.code === 'ER_DUP_ENTRY') return callback(new BoxError(BoxError.ALREADY_EXISTS, 'mail domain already exists'));
+        if (error && error.code === 'ER_NO_REFERENCED_ROW_2') return callback(new BoxError(BoxError.NOT_FOUND), 'no such domain');
+        if (error) return callback(new BoxError(BoxError.DATABASE_ERROR, error));
 
         callback(null);
     });
@@ -53,7 +53,7 @@ function clear(callback) {
 
     // using TRUNCATE makes it fail foreign key check
     database.query('DELETE FROM mail', [], function (error) {
-        if (error) return callback(new DatabaseError(DatabaseError.INTERNAL_ERROR, error));
+        if (error) return callback(new BoxError(BoxError.DATABASE_ERROR, error));
         callback(null);
     });
 }
@@ -64,9 +64,9 @@ function del(domain, callback) {
 
     // deletes aliases as well
     database.query('DELETE FROM mail WHERE domain=?', [ domain ], function (error, result) {
-        if (error && error.code === 'ER_ROW_IS_REFERENCED_2') return callback(new DatabaseError(DatabaseError.IN_USE));
-        if (error) return callback(new DatabaseError(DatabaseError.INTERNAL_ERROR, error));
-        if (result.affectedRows === 0) return callback(new DatabaseError(DatabaseError.NOT_FOUND));
+        if (error && error.code === 'ER_ROW_IS_REFERENCED_2') return callback(new BoxError(BoxError.IN_USE));
+        if (error) return callback(new BoxError(BoxError.DATABASE_ERROR, error));
+        if (result.affectedRows === 0) return callback(new BoxError(BoxError.NOT_FOUND));
 
         callback(null);
     });
@@ -77,8 +77,8 @@ function get(domain, callback) {
     assert.strictEqual(typeof callback, 'function');
 
     database.query('SELECT ' + MAILDB_FIELDS + ' FROM mail WHERE domain = ?', [ domain ], function (error, results) {
-        if (error) return callback(new DatabaseError(DatabaseError.INTERNAL_ERROR, error));
-        if (results.length === 0) return callback(new DatabaseError(DatabaseError.NOT_FOUND));
+        if (error) return callback(new BoxError(BoxError.DATABASE_ERROR, error));
+        if (results.length === 0) return callback(new BoxError(BoxError.NOT_FOUND));
 
         callback(null, postProcess(results[0]));
     });
@@ -88,7 +88,7 @@ function list(callback) {
     assert.strictEqual(typeof callback, 'function');
 
     database.query('SELECT ' + MAILDB_FIELDS + ' FROM mail ORDER BY domain', function (error, results) {
-        if (error) return callback(new DatabaseError(DatabaseError.INTERNAL_ERROR, error));
+        if (error) return callback(new BoxError(BoxError.DATABASE_ERROR, error));
 
         results.forEach(function (result) { postProcess(result); });
 
@@ -118,8 +118,8 @@ function update(domain, data, callback) {
     args.push(domain);
 
     database.query('UPDATE mail SET ' + fields.join(', ') + ' WHERE domain=?', args, function (error, result) {
-        if (error) return callback(new DatabaseError(DatabaseError.INTERNAL_ERROR, error));
-        if (result.affectedRows !== 1) return callback(new DatabaseError(DatabaseError.NOT_FOUND));
+        if (error) return callback(new BoxError(BoxError.DATABASE_ERROR, error));
+        if (result.affectedRows !== 1) return callback(new BoxError(BoxError.NOT_FOUND));
 
         callback(null);
     });
diff --git a/src/mailer.js b/src/mailer.js
index 86623d74e..cebc3bfc4 100644
--- a/src/mailer.js
+++ b/src/mailer.js
@@ -25,6 +25,7 @@ exports = module.exports = {
 };
 
 var assert = require('assert'),
+    BoxError = require('./boxerror.js'),
     constants = require('./constants.js'),
     custom = require('./custom.js'),
     debug = require('debug')('box:mailer'),
@@ -93,7 +94,7 @@ function sendMail(mailOptions, callback) {
         }));
 
         transport.sendMail(mailOptions, function (error) {
-            if (error) return callback(error);
+            if (error) return callback(new BoxError(BoxError.EXTERNAL_ERROR, error));
 
             debug(`Email "${mailOptions.subject}" sent to ${mailOptions.to}`);
 
diff --git a/src/routes/mail.js b/src/routes/mail.js
index 4fef919d7..e895be0d0 100644
--- a/src/routes/mail.js
+++ b/src/routes/mail.js
@@ -36,8 +36,8 @@ exports = module.exports = {
 
 var assert = require('assert'),
     auditSource = require('../auditsource.js'),
+    BoxError = require('../boxerror.js'),
     mail = require('../mail.js'),
-    MailError = mail.MailError,
     HttpError = require('connect-lastmile').HttpError,
     HttpSuccess = require('connect-lastmile').HttpSuccess,
     middleware = require('../middleware/index.js'),
@@ -45,12 +45,28 @@ var assert = require('assert'),
 
 var mailProxy = middleware.proxy(url.parse('http://127.0.0.1:2020'));
 
+function toHttpError(error) {
+    switch (error.reason) {
+    case BoxError.NOT_FOUND:
+        return new HttpError(404, error);
+    case BoxError.ALREADY_EXISTS:
+    case BoxError.CONFLICT:
+        return new HttpError(409, error);
+    case BoxError.BAD_FIELD:
+        return new HttpError(400, error);
+    case BoxError.EXTERNAL_ERROR:
+        return new HttpError(424, error);
+    case BoxError.INTERNAL_ERROR:
+    default:
+        return new HttpError(500, error);
+    }
+}
+
 function getDomain(req, res, next) {
     assert.strictEqual(typeof req.params.domain, 'string');
 
     mail.getDomain(req.params.domain, function (error, result) {
-        if (error && error.reason === MailError.NOT_FOUND) return next(new HttpError(404, error.message));
-        if (error) return next(new HttpError(500, error));
+        if (error) return next(toHttpError(error));
 
         next(new HttpSuccess(200, mail.removePrivateFields(result)));
     });
@@ -62,9 +78,7 @@ function addDomain(req, res, next) {
     if (typeof req.body.domain !== 'string') return next(new HttpError(400, 'domain must be a string'));
 
     mail.addDomain(req.body.domain, function (error) {
-        if (error && error.reason === MailError.NOT_FOUND) return next(new HttpError(404, error.message));
-        if (error && error.reason === MailError.ALREADY_EXISTS) return next(new HttpError(409, 'domain already exists'));
-        if (error) return next(new HttpError(500, error));
+        if (error) return next(toHttpError(error));
 
         next(new HttpSuccess(201, { domain: req.body.domain }));
     });
@@ -92,9 +106,7 @@ function setDnsRecords(req, res, next) {
     req.clearTimeout();
 
     mail.setDnsRecords(req.params.domain, function (error) {
-        if (error && error.reason === MailError.NOT_FOUND) return next(new HttpError(404, error.message));
-        if (error && error.reason === MailError.EXTERNAL_ERROR) return next(new HttpError(424, error.message));
-        if (error) return next(new HttpError(500, error));
+        if (error) return next(toHttpError(error));
 
         next(new HttpSuccess(201));
     });
@@ -104,9 +116,7 @@ function removeDomain(req, res, next) {
     assert.strictEqual(typeof req.params.domain, 'string');
 
     mail.removeDomain(req.params.domain, function (error) {
-        if (error && error.reason === MailError.NOT_FOUND) return next(new HttpError(404, error.message));
-        if (error && error.reason === MailError.IN_USE) return next(new HttpError(409, 'Mail domain is still in use. Remove existing mailboxes'));
-        if (error) return next(new HttpError(500, error));
+        if (error) return next(toHttpError(error));
 
         next(new HttpSuccess(204));
     });
@@ -119,8 +129,7 @@ function getStatus(req, res, next) {
     req.clearTimeout();
 
     mail.getStatus(req.params.domain, function (error, records) {
-        if (error && error.reason === MailError.NOT_FOUND) return next(new HttpError(404, error.message));
-        if (error) return next(new HttpError(500, error));
+        if (error) return next(toHttpError(error));
 
         next(new HttpSuccess(200, records));
     });
@@ -133,9 +142,7 @@ function setMailFromValidation(req, res, next) {
     if (typeof req.body.enabled !== 'boolean') return next(new HttpError(400, 'enabled is required'));
 
     mail.setMailFromValidation(req.params.domain, req.body.enabled, function (error) {
-        if (error && error.reason === MailError.NOT_FOUND) return next(new HttpError(404, error.message));
-        if (error && error.reason === MailError.BAD_FIELD) return next(new HttpError(400, error.message));
-        if (error) return next(new HttpError(500, error));
+        if (error) return next(toHttpError(error));
 
         next(new HttpSuccess(202));
     });
@@ -153,9 +160,7 @@ function setCatchAllAddress(req, res, next) {
     }
 
     mail.setCatchAllAddress(req.params.domain, req.body.addresses, function (error) {
-        if (error && error.reason === MailError.NOT_FOUND) return next(new HttpError(404, error.message));
-        if (error && error.reason === MailError.BAD_FIELD) return next(new HttpError(400, error.message));
-        if (error) return next(new HttpError(500, error));
+        if (error) return next(toHttpError(error));
 
         next(new HttpSuccess(202));
     });
@@ -173,9 +178,7 @@ function setMailRelay(req, res, next) {
     if ('acceptSelfSignedCerts' in req.body && typeof req.body.acceptSelfSignedCerts !== 'boolean') return next(new HttpError(400, 'acceptSelfSignedCerts must be a boolean'));
 
     mail.setMailRelay(req.params.domain, req.body, function (error) {
-        if (error && error.reason === MailError.NOT_FOUND) return next(new HttpError(404, error.message));
-        if (error && error.reason === MailError.BAD_FIELD) return next(new HttpError(400, error.message));
-        if (error) return next(new HttpError(500, error));
+        if (error) return next(toHttpError(error));
 
         next(new HttpSuccess(202));
     });
@@ -188,9 +191,7 @@ function setMailEnabled(req, res, next) {
     if (typeof req.body.enabled !== 'boolean') return next(new HttpError(400, 'enabled is required'));
 
     mail.setMailEnabled(req.params.domain, !!req.body.enabled, auditSource.fromRequest(req), function (error) {
-        if (error && error.reason === MailError.NOT_FOUND) return next(new HttpError(404, error.message));
-        if (error && error.reason === MailError.BAD_FIELD) return next(new HttpError(400, error.message));
-        if (error) return next(new HttpError(500, error));
+        if (error) return next(toHttpError(error));
 
         next(new HttpSuccess(202));
     });
@@ -203,9 +204,7 @@ function sendTestMail(req, res, next) {
     if (!req.body.to || typeof req.body.to !== 'string') return next(new HttpError(400, 'to must be a non-empty string'));
 
     mail.sendTestMail(req.params.domain, req.body.to, function (error) {
-        if (error && error.reason === MailError.NOT_FOUND) return next(new HttpError(404, error.message));
-        if (error && error.reason === MailError.EXTERNAL_ERROR) return next(new HttpError(424, error.message));
-        if (error) return next(new HttpError(500, error));
+        if (error) return next(toHttpError(error));
 
         next(new HttpSuccess(202));
     });
@@ -221,8 +220,7 @@ function listMailboxes(req, res, next) {
     if (!perPage || perPage < 0) return next(new HttpError(400, 'per_page query param has to be a postive number'));
 
     mail.listMailboxes(req.params.domain, page, perPage, function (error, result) {
-        if (error && error.reason === MailError.NOT_FOUND) return next(new HttpError(404, error.message));
-        if (error) return next(new HttpError(500, error));
+        if (error) return next(toHttpError(error));
 
         next(new HttpSuccess(200, { mailboxes: result }));
     });
@@ -233,8 +231,7 @@ function getMailbox(req, res, next) {
     assert.strictEqual(typeof req.params.name, 'string');
 
     mail.getMailbox(req.params.name, req.params.domain, function (error, result) {
-        if (error && error.reason === MailError.NOT_FOUND) return next(new HttpError(404, error.message));
-        if (error) return next(new HttpError(500, error));
+        if (error) return next(toHttpError(error));
 
         next(new HttpSuccess(200, { mailbox: result }));
     });
@@ -247,10 +244,7 @@ function addMailbox(req, res, next) {
     if (typeof req.body.userId !== 'string') return next(new HttpError(400, 'userId must be a string'));
 
     mail.addMailbox(req.body.name, req.params.domain, req.body.userId, auditSource.fromRequest(req), function (error) {
-        if (error && error.reason === MailError.NOT_FOUND) return next(new HttpError(404, error.message));
-        if (error && error.reason === MailError.ALREADY_EXISTS) return next(new HttpError(409, error.message));
-        if (error && error.reason === MailError.BAD_FIELD) return next(new HttpError(400, error.message));
-        if (error) return next(new HttpError(500, error));
+        if (error) return next(toHttpError(error));
 
         next(new HttpSuccess(201, {}));
     });
@@ -263,9 +257,7 @@ function updateMailbox(req, res, next) {
     if (typeof req.body.userId !== 'string') return next(new HttpError(400, 'userId must be a string'));
 
     mail.updateMailboxOwner(req.params.name, req.params.domain, req.body.userId, function (error) {
-        if (error && error.reason === MailError.NOT_FOUND) return next(new HttpError(404, error.message));
-        if (error && error.reason === MailError.BAD_FIELD) return next(new HttpError(400, error.message));
-        if (error) return next(new HttpError(500, error));
+        if (error) return next(toHttpError(error));
 
         next(new HttpSuccess(204));
     });
@@ -276,8 +268,7 @@ function removeMailbox(req, res, next) {
     assert.strictEqual(typeof req.params.name, 'string');
 
     mail.removeMailbox(req.params.name, req.params.domain, auditSource.fromRequest(req), function (error) {
-        if (error && error.reason === MailError.NOT_FOUND) return next(new HttpError(404, error.message));
-        if (error) return next(new HttpError(500, error));
+        if (error) return next(toHttpError(error));
 
         next(new HttpSuccess(201, {}));
     });
@@ -293,8 +284,7 @@ function listAliases(req, res, next) {
     if (!perPage || perPage < 0) return next(new HttpError(400, 'per_page query param has to be a postive number'));
 
     mail.listAliases(req.params.domain, page, perPage, function (error, result) {
-        if (error && error.reason === MailError.NOT_FOUND) return next(new HttpError(404, error.message));
-        if (error) return next(new HttpError(500, error));
+        if (error) return next(toHttpError(error));
 
         next(new HttpSuccess(200, { aliases: result }));
     });
@@ -305,8 +295,7 @@ function getAliases(req, res, next) {
     assert.strictEqual(typeof req.params.name, 'string');
 
     mail.getAliases(req.params.name, req.params.domain, function (error, result) {
-        if (error && error.reason === MailError.NOT_FOUND) return next(new HttpError(404, error.message));
-        if (error) return next(new HttpError(500, error));
+        if (error) return next(toHttpError(error));
 
         next(new HttpSuccess(200, { aliases: result }));
     });
@@ -324,10 +313,7 @@ function setAliases(req, res, next) {
     }
 
     mail.setAliases(req.params.name, req.params.domain, req.body.aliases, function (error) {
-        if (error && error.reason === MailError.NOT_FOUND) return next(new HttpError(404, error.message));
-        if (error && error.reason === MailError.ALREADY_EXISTS) return next(new HttpError(409, error.message));
-        if (error && error.reason === MailError.BAD_FIELD) return next(new HttpError(400, error.message));
-        if (error) return next(new HttpError(500, error));
+        if (error) return next(toHttpError(error));
 
         next(new HttpSuccess(202));
     });
@@ -337,8 +323,7 @@ function getLists(req, res, next) {
     assert.strictEqual(typeof req.params.domain, 'string');
 
     mail.getLists(req.params.domain, function (error, result) {
-        if (error && error.reason === MailError.NOT_FOUND) return next(new HttpError(404, error.message));
-        if (error) return next(new HttpError(500, error));
+        if (error) return next(toHttpError(error));
 
         next(new HttpSuccess(200, { lists: result }));
     });
@@ -349,8 +334,7 @@ function getList(req, res, next) {
     assert.strictEqual(typeof req.params.name, 'string');
 
     mail.getList(req.params.domain, req.params.name, function (error, result) {
-        if (error && error.reason === MailError.NOT_FOUND) return next(new HttpError(404, error.message));
-        if (error) return next(new HttpError(500, error));
+        if (error) return next(toHttpError(error));
 
         next(new HttpSuccess(200, { list: result }));
     });
@@ -369,10 +353,7 @@ function addList(req, res, next) {
     }
 
     mail.addList(req.body.name, req.params.domain, req.body.members, auditSource.fromRequest(req), function (error) {
-        if (error && error.reason === MailError.NOT_FOUND) return next(new HttpError(404, error.message));
-        if (error && error.reason === MailError.ALREADY_EXISTS) return next(new HttpError(409, 'list already exists'));
-        if (error && error.reason === MailError.BAD_FIELD) return next(new HttpError(400, error.message));
-        if (error) return next(new HttpError(500, error));
+        if (error) return next(toHttpError(error));
 
         next(new HttpSuccess(201, {}));
     });
@@ -390,9 +371,7 @@ function updateList(req, res, next) {
     }
 
     mail.updateList(req.params.name, req.params.domain, req.body.members, function (error) {
-        if (error && error.reason === MailError.NOT_FOUND) return next(new HttpError(404, error.message));
-        if (error && error.reason === MailError.BAD_FIELD) return next(new HttpError(400, error.message));
-        if (error) return next(new HttpError(500, error));
+        if (error) return next(toHttpError(error));
 
         next(new HttpSuccess(204));
     });
@@ -403,8 +382,7 @@ function removeList(req, res, next) {
     assert.strictEqual(typeof req.params.name, 'string');
 
     mail.removeList(req.params.name, req.params.domain, auditSource.fromRequest(req), function (error) {
-        if (error && error.reason === MailError.NOT_FOUND) return next(new HttpError(404, error.message));
-        if (error) return next(new HttpError(500, error));
+        if (error) return next(toHttpError(error));
 
         next(new HttpSuccess(204));
     });
diff --git a/src/test/database-test.js b/src/test/database-test.js
index 89f158f39..038a864ad 100644
--- a/src/test/database-test.js
+++ b/src/test/database-test.js
@@ -2006,7 +2006,7 @@ describe('database', function () {
 
         it('cannot add dup entry', function (done) {
             mailboxdb.addMailbox('girish', DOMAIN_0.domain, 'uid-1', function (error) {
-                expect(error.reason).to.be(DatabaseError.ALREADY_EXISTS);
+                expect(error.reason).to.be(BoxError.ALREADY_EXISTS);
                 done();
             });
         });
@@ -2091,7 +2091,7 @@ describe('database', function () {
 
         it('cannot get non-existing group', function (done) {
             mailboxdb.getList('random', DOMAIN_0.domain, function (error) {
-                expect(error.reason).to.be(DatabaseError.NOT_FOUND);
+                expect(error.reason).to.be(BoxError.NOT_FOUND);
                 done();
             });
         });
@@ -2107,7 +2107,7 @@ describe('database', function () {
         it('cannot change name to existing one', function (done) {
             mailboxdb.updateName('support', DOMAIN_0.domain, 'support2', DOMAIN_0.domain, function (error) {
                 expect(error).to.be.ok();
-                expect(error.reason).to.eql(DatabaseError.ALREADY_EXISTS);
+                expect(error.reason).to.eql(BoxError.ALREADY_EXISTS);
 
                 done();
             });
@@ -2138,7 +2138,7 @@ describe('database', function () {
 
                 mailboxdb.getByOwnerId('osticket', function (error) {
                     expect(error).to.be.ok();
-                    expect(error.reason).to.be(DatabaseError.NOT_FOUND);
+                    expect(error.reason).to.be(BoxError.NOT_FOUND);
                     done();
                 });
             });
@@ -2166,7 +2166,7 @@ describe('database', function () {
         it('cannot add non-existing domain', function (done) {
             maildb.add(MAIL_DOMAIN_0.domain + 'nope', {}, function (error) {
                 expect(error).to.be.ok();
-                expect(error.reason).to.be(DatabaseError.NOT_FOUND);
+                expect(error.reason).to.be(BoxError.NOT_FOUND);
 
                 done();
             });