Dovecot: POP3 works in mail client, IMAP doesn't

[trialotto]

@Florian,

If you have the possibility to do a clean, fresh installation, I would certainly recommend it.

In essence, that would rule out any comprises of the server AND some software issues (including those that potentially caused the mail client problems, if it was not the mail client at all).

Regards....

 

[Florian]

Well then that's the plan for now. Thanks for all your help so far!
I'll certainly report back either if email works after the clean install or if it doesn't.

 

[trialotto]

@Florian,

If you are doing a complete reinstall of the server, I would also recommend to use an Ubuntu 14.04 LTS based system (relatively trouble-free) and to use qmail + dovecot.

Regards....

 

[Florian]

Fresh Ubuntu 14.04 installed, Qmail + Dovecot configured and activated, actively whitelisted my IP. Sadly it's all the same as before.

I don't know if it even matters but I'm still going to post the logs.

Thunderbird tries to automatically guess the correct settings:

Mar  5 16:41:32 #server_name# /var/qmail/bin/relaylock[7092]: /var/qmail/bin/relaylock: mail from #my_ip#:54335 (#provider_tld#)
Mar  5 16:41:32 #server_name# /var/qmail/bin/relaylock[7093]: /var/qmail/bin/relaylock: mail from #my_ip#:54337 (#provider_tld#)
Mar  5 16:41:32 #server_name# dovecot: imap-login: Aborted login (no auth attempts in 0 secs): user=<>, rip=#my_ip#, lip=#server_ip#, session=<#session_name#>
Mar  5 16:41:32 #server_name# dovecot: pop3-login: Aborted login (no auth attempts in 0 secs): user=<>, rip=#my_ip#, lip=#server_ip#, session=<#session_name#>
Mar  5 16:41:32 #server_name# dovecot: imap-login: Aborted login (no auth attempts in 0 secs): user=<>, rip=#my_ip#, lip=#server_ip#, session=<#session_name#>
Mar  5 16:41:32 #server_name# dovecot: pop3-login: Aborted login (no auth attempts in 0 secs): user=<>, rip=#my_ip#, lip=#server_ip#, session=<#session_name#>
Mar  5 16:41:32 #server_name# /var/qmail/bin/relaylock[7097]: /var/qmail/bin/relaylock: mail from #my_ip#:54347 (#provider_tld#)
Mar  5 16:41:32 #server_name# /var/qmail/bin/relaylock[7098]: /var/qmail/bin/relaylock: mail from #my_ip#:54349 (#provider_tld#)
Mar  5 16:41:32 #server_name# dovecot: pop3-login: Aborted login (no auth attempts in 0 secs): user=<>, rip=#my_ip#, lip=#server_ip#, session=<#session_name#>
Mar  5 16:41:32 #server_name# /var/qmail/bin/relaylock[7105]: /var/qmail/bin/relaylock: mail from #my_ip#:54353 (#provider_tld#)
Mar  5 16:41:32 #server_name# /var/qmail/bin/relaylock[7106]: /var/qmail/bin/relaylock: mail from #my_ip#:54351 (#provider_tld#)
Mar  5 16:41:32 #server_name# dovecot: pop3-login: Aborted login (no auth attempts in 0 secs): user=<>, rip=#my_ip#, lip=#server_ip#, session=<#session_name#>
Mar  5 16:41:32 #server_name# dovecot: imap-login: Aborted login (no auth attempts in 0 secs): user=<>, rip=#my_ip#, lip=#server_ip#, session=<#session_name#>
Mar  5 16:41:32 #server_name# dovecot: pop3-login: Aborted login (no auth attempts in 0 secs): user=<>, rip=#my_ip#, lip=#server_ip#, session=<#session_name#>
Mar  5 16:41:32 #server_name# dovecot: imap-login: Aborted login (no auth attempts in 0 secs): user=<>, rip=#my_ip#, lip=#server_ip#, session=<#session_name#>
Mar  5 16:41:32 #server_name# dovecot: imap-login: Aborted login (no auth attempts in 0 secs): user=<>, rip=#my_ip#, lip=#server_ip#, session=<#session_name#>
Mar  5 16:41:32 #server_name# dovecot: pop3-login: Aborted login (no auth attempts in 0 secs): user=<>, rip=#my_ip#, lip=#server_ip#, session=<#session_name#>
Mar  5 16:41:32 #server_name# dovecot: imap-login: Aborted login (no auth attempts in 0 secs): user=<>, rip=#my_ip#, lip=#server_ip#, session=<#session_name#>
Mar  5 16:41:32 #server_name# dovecot: pop3-login: Aborted login (no auth attempts in 0 secs): user=<>, rip=#my_ip#, lip=#server_ip#, session=<#session_name#>
Mar  5 16:41:32 #server_name# dovecot: pop3-login: Aborted login (no auth attempts in 0 secs): user=<>, rip=#my_ip#, lip=#server_ip#, session=<#session_name#/jEE8tUwBUsPhi>

Thunderbird was not successful, I enter the correct values and click "Done":

Mar  5 16:41:53 #server_name# dovecot: master: Warning: Killed with signal 15 (by pid=7123 uid=0 code=kill)
Mar  5 16:41:53 #server_name# dovecot: master: Dovecot v2.2.18 starting up for imap, pop3, sieve (core dumps disabled)
Mar  5 16:41:53 #server_name# dovecot: master: Warning: Killed with signal 15 (by pid=7141 uid=0 code=kill)
Mar  5 16:41:53 #server_name# dovecot: master: Dovecot v2.2.18 starting up for imap, pop3, sieve (core dumps disabled)
Mar  5 16:42:19 #server_name# dovecot: imap-login: Disconnected (disconnected before auth was ready, waited 0 secs): user=<>, rip=#my_ip#, lip=#server_ip#, session=<#session_name#>

It doesn't work, to verify everything's running I try to log in with Roundcube. It works:

Mar  5 16:43:44 #server_name# dovecot: imap-login: Login: user=<#mail_address#>, method=DIGEST-MD5, rip=::1, lip=::1, mpid=7182, secured, session=<#session_name#>
Mar  5 16:43:44 #server_name# dovecot: service=imap, user=#mail_address#, ip=[::1]. Disconnected: Logged out rcvd=355, sent=1000
Mar  5 16:43:44 #server_name# dovecot: imap-login: Login: user=<#mail_address#>, method=DIGEST-MD5, rip=::1, lip=::1, mpid=7184, secured, session=<#session_name#>
Mar  5 16:43:45 #server_name# dovecot: service=imap, user=#mail_address#, ip=[::1]. Disconnected: Logged out rcvd=70, sent=620
Mar  5 16:43:45 #server_name# dovecot: imap-login: Login: user=<#mail_address#>, method=DIGEST-MD5, rip=::1, lip=::1, mpid=7187, secured, session=<#session_name#>
Mar  5 16:43:45 #server_name# dovecot: service=imap, user=#mail_address#, ip=[::1]. Disconnected: Logged out rcvd=76, sent=509
Mar  5 16:43:46 #server_name# dovecot: imap-login: Login: user=<#mail_address#>, method=DIGEST-MD5, rip=::1, lip=::1, mpid=7189, secured, session=<#session_name#>
Mar  5 16:43:46 #server_name# dovecot: service=imap, user=#mail_address#, ip=[::1]. Disconnected: Logged out rcvd=257, sent=1005

I try to connect via Windows Mail:

Mar  5 16:50:09 #server_name# dovecot: imap-login: Aborted login (no auth attempts in 0 secs): user=<>, rip=#my_ip#, lip=#server_ip#, session=<#session_name#>
Mar  5 16:50:14 #server_name# dovecot: imap-login: Aborted login (no auth attempts in 0 secs): user=<>, rip=#my_ip#, lip=#server_ip#, session=<#session_name#>
Mar  5 16:50:26 #server_name# dovecot: pop3-login: Aborted login (no auth attempts in 0 secs): user=<>, rip=#my_ip#, lip=#server_ip#, session=<#session_name#>
Mar  5 16:50:27 #server_name# dovecot: pop3-login: Disconnected (no auth attempts in 0 secs): user=<>, rip=#my_ip#, lip=#server_ip#, TLS: SSL_read() failed: error:14094418:SSL routines:SSL3_READ_BYTES:tlsv1 alert unknown ca: SSL alert number 48, session=<#session_name#>
Mar  5 17:05:55 #server_name# dovecot: imap-login: Disconnected (no auth attempts in 0 secs): user=<>, rip=#my_ip#, lip=#server_ip#, TLS: Disconnected, session=<#session_name#>
Mar  5 17:05:55 #server_name# dovecot: imap-login: Disconnected (no auth attempts in 0 secs): user=<>, rip=#my_ip#, lip=#server_ip#, TLS handshaking: SSL_accept() failed: error:1408A10B:SSL routines:SSL3_GET_CLIENT_HELLO:wrong version number, session=<#session_name#>
Mar  5 17:05:55 #server_name# dovecot: imap-login: Disconnected: Too many invalid commands (no auth attempts in 0 secs): user=<>, rip=#my_ip#, lip=#server_ip#, session=<#session_name#>
Mar  5 17:05:55 #server_name# dovecot: imap-login: Disconnected (no auth attempts in 0 secs): user=<>, rip=#my_ip#, lip=#server_ip#, session=<#session_name#>
Mar  5 17:05:56 #server_name# dovecot: imap-login: Disconnected (no auth attempts in 1 secs): user=<>, rip=#my_ip#, lip=#server_ip#, TLS: Disconnected, session=<#session_name#>
Mar  5 17:05:56 #server_name# dovecot: imap-login: Disconnected (no auth attempts in 0 secs): user=<>, rip=#my_ip#, lip=#server_ip#, TLS handshaking: SSL_accept() failed: error:1408A10B:SSL routines:SSL3_GET_CLIENT_HELLO:wrong version number, session=<#session_name#>

It doesn't complain about anything, but from experience Windows Mail never does that anyway.
I try to sync my mails in Windows Mail:

Mar  5 17:08:04 #server_name# dovecot: imap-login: Disconnected (no auth attempts in 0 secs): user=<>, rip=#my_ip#, lip=#server_ip#, TLS: Disconnected, session=<#session_name#/Lb08tGABUsPhi>
Mar  5 17:08:04 #server_name# dovecot: imap-login: Disconnected (no auth attempts in 0 secs): user=<>, rip=#my_ip#, lip=#server_ip#, TLS handshaking: SSL_accept() failed: error:1408A10B:SSL routines:SSL3_GET_CLIENT_HELLO:wrong version number, session=<#session_name#>
Mar  5 17:08:04 #server_name# dovecot: imap-login: Disconnected: Too many invalid commands (no auth attempts in 0 secs): user=<>, rip=#my_ip#, lip=#server_ip#, session=<#session_name#>
Mar  5 17:08:05 #server_name# dovecot: imap-login: Disconnected (no auth attempts in 0 secs): user=<>, rip=#my_ip#, lip=#server_ip#, session=<#session_name#>
Mar  5 17:08:05 #server_name# dovecot: imap-login: Disconnected (no auth attempts in 0 secs): user=<>, rip=#my_ip#, lip=#server_ip#, TLS: Disconnected, session=<#session_name#>
Mar  5 17:08:05 #server_name# dovecot: imap-login: Disconnected (no auth attempts in 0 secs): user=<>, rip=#my_ip#, lip=#server_ip#, TLS handshaking: SSL_accept() failed: error:1408A10B:SSL routines:SSL3_GET_CLIENT_HELLO:wrong version number, session=<#session_name#>

I don't know what else to do. This is getting at least a little bit frustrating.

(By the way: Is it paranoid or rather common to anonymize all the information like I do?)