diff --git a/migrations/20200331164304-apps-alter-mailboxDomain.js b/migrations/20200331164304-apps-alter-mailboxDomain.js
new file mode 100644
index 000000000..14346079e
--- /dev/null
+++ b/migrations/20200331164304-apps-alter-mailboxDomain.js
@@ -0,0 +1,28 @@
+'use strict';
+
+let async = require('async');
+
+exports.up = function(db, callback) {
+    db.runSql('ALTER TABLE apps MODIFY mailboxDomain VARCHAR(128)', [], function (error) { // make it nullable
+        if (error) console.error(error);
+
+        // clear mailboxName/Domain for apps that do not use mail addons
+        db.all('SELECT * FROM apps', function (error, apps) {
+            if (error) return callback(error);
+
+            async.eachSeries(apps, function (app, iteratorDone) {
+                var manifest = JSON.parse(app.manifestJson);
+                if (manifest.addons['sendmail'] || manifest.addons['recvmail']) return iteratorDone();
+
+                db.runSql('UPDATE apps SET mailboxName=?, mailboxDomain=? WHERE id=?', [ null, null, app.id ], iteratorDone);
+            }, callback);
+        });
+    });
+};
+
+exports.down = function(db, callback) {
+    db.runSql('ALTER TABLE apps MODIFY manifestJson VARCHAR(128) NOT NULL', [], function (error) {
+        if (error) console.error(error);
+        callback(error);
+    });
+};
diff --git a/migrations/schema.sql b/migrations/schema.sql
index 6f1b460e9..41e14a9c4 100644
--- a/migrations/schema.sql
+++ b/migrations/schema.sql
@@ -79,8 +79,8 @@ CREATE TABLE IF NOT EXISTS apps(
     reverseProxyConfigJson TEXT, // { robotsTxt, csp }
     enableBackup BOOLEAN DEFAULT 1, // misnomer: controls automatic daily backups
     enableAutomaticUpdate BOOLEAN DEFAULT 1,
-    mailboxName VARCHAR(128), // mailbox of this app. default allocated as '.app'
-    mailboxDomain VARCHAR(128) NOT NULL, // mailbox domain of this apps
+    mailboxName VARCHAR(128), // mailbox of this app
+    mailboxDomain VARCHAR(128), // mailbox domain of this apps
     label VARCHAR(128),     // display name
     tagsJson VARCHAR(2048), // array of tags
     dataDir VARCHAR(256) UNIQUE,
diff --git a/src/addons.js b/src/addons.js
index d6e54e4e8..a091f3699 100644
--- a/src/addons.js
+++ b/src/addons.js
@@ -524,7 +524,14 @@ function teardownAddons(app, addons, callback) {
         debugApp(app, 'Tearing down addon %s with options %j', addon, addons[addon]);
 
         KNOWN_ADDONS[addon].teardown(app, addons[addon], iteratorCallback);
-    }, callback);
+    }, function (error) {
+        if (error) return callback(error);
+
+        if (app.manifest.addons.sendmail || app.manifest.addons.recvmail) return callback();
+
+        // clear mailbox name if neither are used
+        appdb.update(app.id, { mailboxName: null, mailboxDomain: null }, callback);
+    });
 }
 
 function backupAddons(app, addons, callback) {
diff --git a/src/apps.js b/src/apps.js
index 6e39b6014..d164c504b 100644
--- a/src/apps.js
+++ b/src/apps.js
@@ -699,6 +699,10 @@ function validateLocations(locations, callback) {
     });
 }
 
+function hasMailAddon(manifest) {
+    return manifest.addons.sendmail || manifest.addons.recvmail;
+}
+
 function install(data, auditSource, callback) {
     assert(data && typeof data === 'object');
     assert.strictEqual(typeof auditSource, 'object');
@@ -757,7 +761,8 @@ function install(data, auditSource, callback) {
     error = validateEnv(env);
     if (error) return callback(error);
 
-    const mailboxName = mailboxNameForLocation(location, manifest);
+    const mailboxName = hasMailAddon(manifest) ? mailboxNameForLocation(location, manifest) : null;
+    const mailboxDomain = hasMailAddon(manifest) ? domain : null;
     const appId = uuid.v4();
 
     if (icon) {
@@ -785,7 +790,7 @@ function install(data, auditSource, callback) {
             sso: sso,
             debugMode: debugMode,
             mailboxName: mailboxName,
-            mailboxDomain: domain,
+            mailboxDomain: mailboxDomain,
             enableBackup: enableBackup,
             enableAutomaticUpdate: enableAutomaticUpdate,
             alternateDomains: alternateDomains,
@@ -1026,6 +1031,8 @@ function setMailbox(app, mailboxName, mailboxDomain, auditSource, callback) {
     let error = checkAppState(app, exports.ISTATE_PENDING_RECREATE_CONTAINER);
     if (error) return callback(error);
 
+    if (!hasMailAddon(app.manifest)) return callback(new BoxError(BoxError.BAD_FIELD, 'App does not use mail addons'));
+
     mail.getDomain(mailboxDomain, function (error) {
         if (error) return callback(error);
 
@@ -1033,7 +1040,7 @@ function setMailbox(app, mailboxName, mailboxDomain, auditSource, callback) {
             error = mail.validateName(mailboxName);
             if (error) return callback(new BoxError(BoxError.BAD_FIELD, error.message, { field: 'mailboxName' }));
         } else {
-            mailboxName = mailboxNameForLocation(app.location, app.manifest);
+            mailboxName = mailboxNameForLocation(app.location, app.domain, app.manifest);
         }
 
         const task = {
@@ -1161,7 +1168,10 @@ function setLocation(app, data, auditSource, callback) {
     }
 
     // move the mailbox name to match the new location
-    if (app.mailboxName.endsWith('.app')) values.mailboxName = mailboxNameForLocation(values.location, app.manifest);
+    if (hasMailAddon(app.manifest) && app.mailboxName.endsWith('.app')) {
+        values.mailboxName = mailboxNameForLocation(values.location, app.manifest);
+        values.mailboxDomain = values.domain;
+    }
 
     if ('alternateDomains' in data) {
         values.alternateDomains = data.alternateDomains;
@@ -1532,7 +1542,12 @@ function clone(app, data, user, auditSource, callback) {
         error = validatePortBindings(portBindings, manifest);
         if (error) return callback(error);
 
-        const mailboxName = app.mailboxName.endsWith('.app') ? mailboxNameForLocation(location, manifest) : app.mailboxName;
+        let mailboxName = null, mailboxDomain = null;
+        if (hasMailAddon(manifest)) {
+            mailboxName = app.mailboxName.endsWith('.app') ? mailboxNameForLocation(location, manifest) : app.mailboxName;
+            mailboxDomain = domain;
+        }
+
         const locations = [{subdomain: location, domain}];
         validateLocations(locations, function (error, domainObjectMap) {
             if (error) return callback(error);
@@ -1546,7 +1561,7 @@ function clone(app, data, user, auditSource, callback) {
                 accessRestriction: app.accessRestriction,
                 sso: !!app.sso,
                 mailboxName: mailboxName,
-                mailboxDomain: domain,
+                mailboxDomain: mailboxDomain,
                 enableBackup: app.enableBackup,
                 reverseProxyConfig: app.reverseProxyConfig,
                 env: app.env,