==== REQUIRED BASIC INFO OF YOUR IREDMAIL SERVER ====
- iRedMail version (check /etc/iredmail-release):
- Linux/BSD distribution name and version:
- Store mail accounts in which backend (LDAP/MySQL/PGSQL):
- Web server (Apache or Nginx):
- Manage mail accounts with iRedAdmin-Pro?
- [IMPORTANT] Related original log or error message is required if you're experiencing an issue.
======== REQUIRED BASIC INFO OF YOUR IREDMAIL SERVER ====
- iRedMail version (check /etc/iredmail-release):
- Linux/BSD distribution name and version:
- Store mail accounts in which backend (LDAP/MySQL/PGSQL):
- Web server (Apache or Nginx):
- Manage mail accounts with iRedAdmin-Pro?
- [IMPORTANT] Related original log or error message is required if you're experiencing an issue.
======== Required information ====
- iRedMail version (check /etc/iredmail-release): 0.9.8
- Linux/BSD distribution name and version: Ubuntu 18.04 Server LTS
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): MySQL
- Web server (Apache or Nginx): Nginx
- Manage mail accounts with iRedAdmin-Pro? Yes
====

I followed the manual.

My /etc/postfix/main.cf looks now like:

# Sender restrictions
smtpd_sender_restrictions =
    permit_mynetworks
    permit_sasl_authenticated
    #reject_unknown_sender_domain
    #reject_non_fqdn_sender
    #reject_unlisted_sender
    #permit_mynetworks
    #permit_sasl_authenticated
    #check_sender_access pcre:/etc/postfix/sender_access.pcre

/opt/iredapd/settings.py

# 2018-05-22 added
mynetworks = ['127.0.0.1',' [::1]','10.10.100.100','10.10.0.1']
ALLOWED_FORGED_SENDERS = ['liss2@some.domain','user1@some.domain','user2@other.domain']

From an Exchange server they want to use user2@other.domain as authenticator for all accounts.

Guess, it doesn't work. In the mail is:

Jul 13 19:45:07 mail postfix/submission/smtpd[12727]: NOQUEUE: reject: RCPT from p5DD429FD.dip0.t-ipconnect.de[11.222.33.444]: 554 5.7.1 <recipient@db-123.de>: Recipient address rejected: Sender is not same as SMTP authenticate username; from=<some.user@other.domain> to=<Trecipient@db-123.de> proto=ESMTP helo=<SRV-01-AD.other.doamain.local>

Authenticator is 'user2@other.domain - he can send/receive mails, others receive only.

What did I wrong?

Greetings,
Peter