Page 1 of 1

Mail Port Block (Frontier, Comcast, Others) Work-Around

Posted: Tue Apr 08, 2014 8:53 pm
by Nanook
Most ISPs block outgoing connections to port 25 because so many spam programs and viruses abuse this port to send spam or viruses without any authentication requirements to slow them down.

To get around these you can use one of our alternate ports:

Port 465 requires TLS and authentication
Port 587 requires authentication, STARTTLS optional.
Port 2525 requires authentication or POP-before-SMTP,
STARTTLS optional.

However, Frontier it seems is also blocking these, so
also listens to port 80 with the same configuration as port 587.