==== REQUIRED BASIC INFO OF YOUR IREDMAIL SERVER ====
- iRedMail version (check /etc/iredmail-release): 1.3
- Deployed with iRedMail Easy or the downloadable installer? Downloadable
- Linux/BSD distribution name and version: CentOS 7.8.2003
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): MariaDB
- Web server (Apache or Nginx): Nginx
- Manage mail accounts with iRedAdmin-Pro? Yes. 4.4
- [IMPORTANT] Related original log or error message is required if you're experiencing an issue.
====

   Hello,

After upgrading iRedAPD from 3.6 to 4.1 version, I started to find many warning messages in maillog:

Jul  3 10:30:20 mail postfix/submission/smtpd[1070]: connect from unknown[x.x.x.x]
Jul  3 10:30:20 mail postfix/submission/smtpd[1070]: Anonymous TLS connection established from unknown[x.x.x.x]: TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)
Jul  3 10:30:20 mail postfix/submission/smtpd[1070]: 548C3200B732: client=unknown[x.x.x.167], sasl_method=LOGIN, sasl_username=user@domain.ltd
Jul  3 10:30:20 mail postfix/cleanup[16290]: 548C3200B732: message-id=<014701d6510b$ce2faf50$6a8f0df0$@domain.ltd>
Jul  3 10:30:21 mail postfix/submission/smtpd[1070]: warning: problem talking to server 127.0.0.1:7777: Success
Jul  3 10:30:21 mail postfix/submission/smtpd[1070]: 548C3200B732: reject: END-OF-MESSAGE from unknown[x.x.x.x]: 451 4.3.5 Server configuration problem; from=<user@domain.ltd> to=<user1@domain1.ltd> proto=ESMTP helo=<hostname>
Jul  3 10:30:23 mail postfix/submission/smtpd[1070]: disconnect from unknown[x.x.x.x]

Jul  3 10:30:20 mail journal: iredapd Whitelisted: wblist=(19, 1740, 'W')
Jul  3 10:30:20 mail journal: iredapd [x.x.x.x] RCPT, user@domain.ltd => user1@domain1.ltd, OK [sasl_username=user@domain.ltd, sender=user@domain.ltd, client_name=unknown, reverse_client_name=unknown, helo=hostname, encryption_protocol=TLSv1.2, encryption_cipher=DHE-RSA-AES256-GCM-SHA384, server_port=, process_time=0.0073s]

Regards
Marius