Fail2ban secured smtp

fail2ban secured smtp

RealSender relies on the Fail2ban server application to secure your dedicated smtp.
This protects against unauthorized access and DOS (Denial Of Service) attacks.

After three failed attempts, the source IP is blocked and banned.


The causes of the blacklisting could be:


The result of the block is that the smtp server no longer responds to connection attempts,
the computer making the request will receive this message:

connect to address 93.184.216.34: Connection refused

How to deal with accidentally banned IP addresses:

2021-08-26 01:38:01,199 fail2ban.filter         [19671]: INFO    [smtp] Found 93.184.216.34 - 2021-08-26 01:38:00
2021-08-26 01:38:01,201 fail2ban.filter         [19671]: INFO    [smtp] Found 93.184.216.34 - 2021-08-26 01:38:01
2021-08-26 01:38:01,404 fail2ban.filter         [19671]: INFO    [smtp] Found 93.184.216.34 - 2021-08-26 01:38:01
2021-08-26 01:38:01,972 fail2ban.actions        [19671]: NOTICE  [smtp] Ban 93.184.216.34
2021-08-23 07:00:12,501 fail2ban.filter         [30057]: INFO    [smtp] Ignore 93.184.216.34 by ip
2021-08-23 07:00:12,501 fail2ban.filter         [30057]: INFO    [smtp] Ignore 93.184.216.34 by ip
2021-08-23 07:00:13,115 fail2ban.filter         [30057]: INFO    [smtp] Ignore 93.184.216.34 by ip