Comment 1 for bug 265965

In particular, all mails sent from mailman have the port number on the end of the reply address. This causes certain mail servers to reject the messagges.

A workaround is to have two web listeners, one on port 80 and one on the real port e.g. 8080. One then redirects all mailman requests on port 80 to the other port. I do this because I have to have my main web server and my mailman web server running as different users.

The problem is current in 2.1.12