Relative Content

Tag Archive for postfix-mta

Postfix responds locally but not remotely – no it is not the firewall

I’ve got Postfix setup on a new Ubuntu 24.04 server. If I telnet to it locally it responds with the SMTP banner as expected. If I telnet to it from an external source though it opens the port and then does nothing i.e. I get a blank screen and a “452 syntax error(connecting)” error for any command I send. Obviously it is not a firewall issue as postfix answers, it just seems to not want to service requests from the external network.