==== REQUIRED BASIC INFO OF YOUR IREDMAIL SERVER ====
- iRedMail version (check /etc/iredmail-release):
- Deployed with iRedMail Easy or the downloadable installer?
- Linux/BSD distribution name and version:
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): LDAP
- Web server (Apache or Nginx): Nginx
- Manage mail accounts with iRedAdmin-Pro? Not yet
- [IMPORTANT] Related original log or error message is required if you're experiencing an issue.
====

I need to add "posixAccount" objectClass by default to all created new mail users , the default ones now (inteOrgperson, mailUser, shadowAccount, amavisAccount) with its required attributes (uidNumber, gidNumber) to be auto incremented.
I tried to edit in "iredadmin/settings.py" file and add the following :

ADDITIONAL_USER_OBJECTCLASSES = ['posixAccount']
ADDITIONAL_USER_ATTRIBUTES = [('uidNumber', ['%(next_uid)d']),
                                 ('gidNumber', ['%(next_gid)d'])]

with no change happen at test,
Is that applicable to do, or applicable on Pro plan?

Also, need to edit default loginShell for users to be Bash instead of default one "csh"