Hello :)
I have a strange issue which is causing our clients to be banned by the "plesk-postfix" Fail2Ban jail.
These clients were recently migrated from Plesk 10 to the current Plesk 12 server.
We are seeing the following in /var/log/maillog
Sep 30 13:22:14 plesk-1 postfix/smtpd[276918]...