==== REQUIRED BASIC INFO OF YOUR IREDMAIL SERVER ====
- iRedMail version (check /etc/iredmail-release): 1.6.3
- Deployed with iRedMail Easy or the downloadable installer?
- Linux/BSD distribution name and version: Ubuntu 22.04.2
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): MySQL
- Web server (Apache or Nginx):Nginx
- Manage mail accounts with iRedAdmin-Pro? yes
- [IMPORTANT] Related original log or error message is required if you're experiencing an issue.
====
- virtualization - Proxmox - lxc container

Hi,
I need to open addition port for postfix, I went trough https://docs.iredmail.org/additional.smtp.port.html
- port on fw is open
- from operating system I see that postfix is listening on port 2525
but I can't connect.

I did some exercise:
- installed this same linux version
- installed iredmail 1.6.3 (but without bail2ban)
and I'm able to connect.

Diff between test and prod:
- IP
- on prod I have fail2bann (but turning off fail2bann don't work, I still can't connect to 2525)

How to solve ?