A message that you sent could not be delivered to one or more of its recipients. This is a permanent error. The following address(es) failed: firstname.lastname@example.org . Mailing to remote domains not supported.
This is a commonly noticed error in new servers or servers with newly installed mail server such as Exim4, when sending mails to external mail addresses.
In our experience providing Technical Support Services for web hosting companies, we come across many sorts of email errors, and resolve them for our customers.
Today, we’ll see what causes the error ‘mailing to remote domains not supported’ and how we fix it in Exim4 servers.