I've recently upgraded my server (Centos) from 6.3 to 6.6 and upgraded IredMail (LDAP) from 0.8.6 to 0.9.1.
Now some of our multifunctionals and google get errors when sending e-mails.
Too many of those and fail2ban bans the ipadresses for an hour so they can't send e-mails.
The emails are sent to the recipient when the account is not banned.
I'm using Postfix 2.11.0 and dovecot 2.1.17
Here is a part of the messages in te maillog:
Jun 16 11:44:52 vcn-mail postfix/smtpd[22742]: warning: unknown[192.168.17.5]: SASL PLAIN authentication failed:
Jun 16 12:17:26 vcn-mail postfix/smtpd[29500]: warning: mail-qg0-f51.google.com[209.85.192.51]: SASL PLAIN authentication failed:
Jun 16 12:17:26 vcn-mail postfix/smtpd[29480]: warning: mail-qk0-f180.google.com[209.85.220.180]: SASL PLAIN authentication failed:
Jun 16 13:54:47 vcn-mail postfix/smtpd[20366]: warning: unknown[192.168.13.10]: SASL PLAIN authentication failed:
Jun 16 13:54:55 vcn-mail postfix/smtpd[20087]: warning: unknown[192.168.13.10]: SASL PLAIN authentication failed:
Jun 16 13:55:02 vcn-mail postfix/smtpd[20366]: warning: unknown[192.168.13.10]: SASL PLAIN authentication failed:
Jun 16 13:55:09 vcn-mail postfix/smtpd[16393]: warning: unknown[192.168.13.10]: SASL PLAIN authentication failed:
Jun 16 13:55:16 vcn-mail postfix/smtpd[17091]: warning: unknown[192.168.13.10]: SASL PLAIN authentication failed:
Jun 16 13:55:23 vcn-mail postfix/smtpd[20087]: warning: unknown[192.168.13.10]: SASL PLAIN authentication failed:
Jun 16 13:55:30 vcn-mail postfix/smtpd[20086]: warning: unknown[192.168.13.10]: SASL PLAIN authentication failed:
Jun 16 14:05:52 vcn-mail postfix/smtpd[20365]: warning: unknown[80.100.108.225]: SASL PLAIN authentication failed:
Jun 16 14:14:34 vcn-mail postfix/smtpd[20365]: warning: mail-qc0-f182.google.com[209.85.216.182]: SASL PLAIN authentication failed: