Symptoms

Email does not get delivered to username@example.com, the following errors appear in /var/log/maillog:


Sep  5 16:47:41 c16 dovecot_authdb_plesk[1377]: No such user 'username@example.com' in mail authorization database
Sep  5 16:47:41 c16 dovecot: auth: plesk(username@example.com): Mail account information for user='username@example.com' was not found
Sep  5 16:47:41 c16 dovecot: auth: Debug: userdb out: NOTFOUND#0111
Sep  5 16:47:41 c16 dovecot: service=lda, user=username@example.com, ip=[]. Debug: auth input:
Sep  5 16:47:41 c16 postfix/pipe[14513]: E141A88AA5: to=<username@example.com, relay=plesk_virtual, delay=2, delays=2/0/0/0.06, dsn=4.2.1, status=deferred (Message can not be delivered at this time )

The same errors may appear after switching from Courier to Dovecot if messages are forwarded internally.

Cause

The mail account (recipient) has an empty password

Resolution

Set password at Domains > example.com > Email Addresses > username@example.com

If there are numerous mail accounts affected by the issue, the following steps can automate the resolution process:

1. Find all accounts affected by the issue log in to Plesk database and make a query:

   MYSQL_PWD=`cat /etc/psa/.psa.shadow`  mysql -uadmin psa -Ne "select concat(m.mail_name,'@',d.name) as mailbox, a.type, a.password from domains d, mail m, accounts a where m.dom_id=d.id and m.account_id=a.id and m.postbox='true' and a.type='plain';" > /root/select.sql
   

2. Make a mass password set:

   # while read i; do /usr/local/psa/bin/mail -u $i -passwd '&cOxq151'; done < /root/select.sql