CentOS 8 / Almalinux 8 mailman - unkonwn user in virtual mailbox table + mailman.conf for httpd

I post that issue here, firstly posted in forum:

https://www.howtoforge.com/community/threads/centos-8-almalinux-8-mailman-unkonwn-user-in-virtual-mailbox-table.89076/

I found a solution and post it on forum and I'll be happy if you implement that in next version of ispconfig and update centos 8 and/or create a new perfect server tutorial for AlmaLinux 8.

Edited by Paco