Hello, I used to set up ISPConfig3 on a single server with a domain name for everything. It worked very well. On my new ISPConfig3 setup, my ISPConfig3 host has a separate host name which hosts several web domains and email domains. For my first email domain, I created its DKIM, SPF, DMARC records. It can receive incoming 3rd party emails but its outgoing emails are rejected by 3rd party email servers. So how do I correct it? Here is a sample of error log recorded by postfix:
Yes, I disable my CSF firewall and the emails pass. I must have configured something wrong. You are the de facto ISPconfig expert! I can tell you. Those on stuckoverflow are mostly wrong and misleading.
