diff --git a/src/mail.js b/src/mail.js
index c49ac1723..11d469150 100644
--- a/src/mail.js
+++ b/src/mail.js
@@ -1168,6 +1168,7 @@ async function addMailbox(name, domain, data, auditSource) {
 
     [error] = await safe(database.query('INSERT INTO mailboxes (name, type, domain, ownerId, ownerType, active) VALUES (?, ?, ?, ?, ?, ?)', [ name, exports.TYPE_MAILBOX, domain, ownerId, ownerType, active ]));
     if (error && error.code === 'ER_DUP_ENTRY') throw new BoxError(BoxError.ALREADY_EXISTS, 'mailbox already exists');
+    if (error && error.code === 'ER_NO_REFERENCED_ROW_2' && error.sqlMessage.includes('mailboxes_domain_constraint')) throw new BoxError(BoxError.NOT_FOUND, `no such domain '${domain}'`);
     if (error) throw error;
 
     eventlog.add(eventlog.ACTION_MAIL_MAILBOX_ADD, auditSource, { name, domain, ownerId, ownerType, active });