Just spotted a few failed login attempts from gateway (172.22.1.1) in postfix logs:
2024-04-03T02:40:25+01:00 localhost.localdomain docker/mailcowdockerized-postfix-mailcow-1[4053245]: Apr 3 02:40:25 0c1f8ef8e5e9 postfix/smtps/smtpd[30383]: warning: unknown[172.22.1.1]: SASL LOGIN authentication failed: UGFzc3dvcmQ6, sasl_username=xxxxxx@domain.com
2024-04-03T22:36:55+01:00 localhost.localdomain docker/mailcowdockerized-postfix-mailcow-1[4053245]: Apr 3 22:36:55 0c1f8ef8e5e9 postfix/smtps/smtpd[42463]: warning: unknown[172.22.1.1]: SASL LOGIN authentication failed: UGFzc3dvcmQ6, sasl_username=xxxxxx@domain.com
2024-04-03T22:37:20+01:00 localhost.localdomain docker/mailcowdockerized-postfix-mailcow-1[4053245]: Apr 3 22:37:20 0c1f8ef8e5e9 postfix/smtps/smtpd[42463]: warning: unknown[172.22.1.1]: SASL LOGIN authentication failed: UGFzc3dvcmQ6, sasl_username=xxxxxx@domain.com
Any clue what that could be and why that wouldn’t use external IP instead?