Today I was configuring my existing email server with a smarthost to relay emails to a test domain hosted by i-mscp.
Everything was fine. DNS, MX Records for lan resolutions etc.
But when I tried to send email to that domain I got in return:
It seems that postfix policyd doesn't care of my local DNS configuration (correct me if I'm wrong) and look for an answer on internet.
At first I look in this forum to find a quick solution, but I found only a few discussions in the German Corner..
So I decided to create a whitelist for my internal mail server.
I hope this could help someone else
1. Make a copy of your /etc/postfix/main.cf
2. Edit /etc/postfix/main.cf
3. Look for smtpd_recipient_restrictions =
4. Just above check_policy_service (.....) insert this line
You can change the filepath or filename, but do not forget the comma at the end.
5. Create the file /etc/postfix/policyd_weight_client_whitelist (or however you named it jist above)
The IP is just an example. Use the IP you want to whitelist.
6. Reload postfix daemon
7. execute postmap /etc/postfix/policyd_weight_client_whitelist