Webmail - Connection to IMAP server failed

[Xiron]

cPanel 11.36.1 (build 5)

Can not access webmail, for any of the domains hosted on the server.

Roundcube reports: connection to IMAP server failed
Horde reports: Login failed because your username or password was entered incorrectly.
SquirrelMail: just returns a blank page

Can access mail on all the domains via mail clients such as Thunderbird or Outlook, only a problem with webmail.

Mail logs don't really show anything, except a lot of: no host name found for IP address, including no host name found for IP address localhost, really don't know if this is connected.

The domains are in /etc/localdomains, resolv.conf & hosts are correct.

Have done upcp, restarting dovecot, reinstall webmail apps, various other usual things.

Have attempted with firewall (CSF) enabled & disabled, not a firewall problem.

Have opened a ticket with cPanel. Tech has done just all the things I have done and passed it to 2nd line support, still waiting for them to reply. Been down for over 2 days now.

Anybody any ideas how to fix this?
Thanks

 

[Infopro]

Have opened a ticket with cPanel. Tech has done just all the things I have done and passed it to 2nd line support, still waiting for them to reply. Been down for over 2 days now.

Could you post the ticket ID here please?

 

[fcastro86]

I would suggest to check

/etc/relayhosts /etc/relayhostsusers

Check if they are empty