Webmail not working

Hello,

Webmail is not working. I get the following error:

An error occurred listing mail in this folder: Failed to login to POP3 server : [AUTHENTICATIONFAILED] Authentication failed.

Maillog shows a blank user:

Jan 27 20:28:39 2819 dovecot: imap-login: Disconnected (auth failed, 1 attempts in 17 secs): user=<>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, secured, session=<QHrHZnaAyLF/AAAB> Jan 27 20:28:39 2819 dovecot: imap-login: Disconnected (auth failed, 1 attempts in 34 secs): user=<>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, secured, session=<MrzDZXaAtLF/AAAB> Jan 27 20:28:39 2819 dovecot: imap-login: Disconnected (auth failed, 1 attempts in 51 secs): user=<>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, secured, session=<FFfCZHaArLF/AAAB> Jan 27 20:28:56 2819 dovecot: imap-login: Disconnected (auth failed, 1 attempts in 34 secs): user=<>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, secured, session=<FIjHZnaAyrF/AAAB> Jan 27 20:28:56 2819 dovecot: imap-login: Disconnected (auth failed, 1 attempts in 17 secs): user=<>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, secured, session=<DDPLZ3aA1LF/AAAB> Jan 27 20:28:56 2819 dovecot: imap-login: Disconnected (auth failed, 1 attempts in 51 secs): user=<>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, secured, session=<a8THZXaAtrF/AAAB> Jan 27 20:29:30 2819 dovecot: imap-login: Disconnected (auth failed, 1 attempts in 17 secs): user=<>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, secured, session=<23/SaXaA7LF/AAAB> Jan 27 20:29:30 2819 dovecot: imap-login: Disconnected (auth failed, 1 attempts in 34 secs): user=<>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, secured, session=<q8POaHaA4LF/AAAB> Jan 27 20:29:30 2819 dovecot: imap-login: Disconnected (auth failed, 1 attempts in 51 secs): user=<>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, secured, session=<opbSZ3aA1rF/AAAB>

I tried on several accounts (different domains) and get the same issue.

I tried restarting dovecot but it has not fixed it.

Any idea will be greatly appreciated.

Thanks,

Max