==== REQUIRED BASIC INFO OF YOUR IREDMAIL SERVER ====
- iRedMail version (0.9.4):
- Deployed with iRedMail Easy or the downloadable installer?
- Linux/BSD distribution name and version: Ubuntu 16.04
- Store mail accounts in which backend (MySQL):
- Web server (Apache):
- Manage mail accounts with iRedAdmin-Pro?
- [IMPORTANT] Related original log or error message is required if you're experiencing an issue.
====

Hello guys,

I am new to this forum however i am using iRedMail for more then 2 years now.

Now i got a small problem and i know this function exists before.

Case: When a server logging in by using smtp program (Like: SSMTP) to send emails, the mail can get rejected because the FROM Email address does not match with the one thats listed. Recently i discovered that i am able to mail from noexistinguser@existingdomain.nl  while logging in via SSTMP with valid credentials (valid email + password). ).

This is my main.cf
# HELO restriction
smtpd_helo_required = yes
smtpd_helo_restrictions =
    permit_mynetworks
    permit_sasl_authenticated
    reject_non_fqdn_helo_hostname
    reject_invalid_helo_hostname
    check_helo_access pcre:/etc/postfix/helo_access.pcre

# Sender restrictions
smtpd_sender_restrictions =
    reject_unknown_sender_domain
    reject_non_fqdn_sender
    reject_unlisted_sender
    permit_sasl_authenticated
    permit_mynetworks
    reject_rbl_client zen.spamhaus.org=127.0.0.[2..11]
    reject_rbl_client b.barracudacentral.org=127.0.0.2
    check_sender_access pcre:/etc/postfix/reject_domain

# Recipient restrictions
smtpd_recipient_restrictions =
    reject_unknown_recipient_domain
    reject_non_fqdn_recipient
    reject_unlisted_recipient
    check_policy_service inet:127.0.0.1:7777
    permit_mynetworks
    permit_sasl_authenticated
    reject_unauth_destination
    reject_unlisted_sender
    reject_rbl_client zen.spamhaus.org=127.0.0.[2..11]
    reject_rbl_client b.barracudacentral.org=127.0.0.2
    check_sender_access pcre:/etc/postfix/reject_domains

As far i my knowledge reaches i am getting the impression that some link is broken to the virtual user table.

I searched en configured alot but i am not getting the impression that its working.

Hopefully you guys can help me out.

Thanks!