I have set up an ISPConfig server to host email for several domains and I am having a problem with mail sent from this server not being delivered to some, but not all, valid domains.
When mail is rejected, it contains an error message similar to the following:
firstname.lastname@example.org: Host or domain name not found for name=comcast.net Type=A: Host found but no data record of requested type
I thought that my domain may have gotten blacklisted, but I didn't find any listings when checked the domain against several BLs.
AFAIK, Type A records are IPv4 addresses and should always exist if a DNS record exists.
I'm at a loss.
Can anyone shed some light on what this message is telling me?