I have a similar issue to the one one the link below https://www.howtoforge.com/communit...onfig-3-1-on-ubuntu-18-04-server.81898/page-2 I have followed the suggestions on this thread but I am not able to receive mail from external domain. I can send to external domains though I was upgrading my email server to ISPConfig Version: 3.2b2 on Ubuntu 20.04. I have pfsense firewall and have done port forwarding for ports 587,993,995 to my server.
I tried as suggested, still not receiving from external domains. I have confirmed my dns records with my dns hosting /ISP provider, port 25 is open. mxtoolbox mail Tester shows that there is no connectivity to the email server
There is tutorial: https://www.howtoforge.com/how-to-install-an-email-server-with-ispconfig-on-debian-10/ Read also comments.
