accepting your mail on port 25. =20
If so, that may eventually stop working at which point you'll need to
switch to port 587.

In early 2009, there was discussion on this list about Comcast blocking
port 25.   =20
http://archives.mn-linux.org/pipermail/tclug-list/2009-February/thread.h
tml =20

I was unaffected at the time, but in February of 2010,  Comcast stopped
accepting my port 25 connections. =20

    $ telnet smtp.comcast.net 25
    Trying 76.96.30.117...
    telnet: Unable to connect to remote host: Connection timed out

I called Comcast and they said "that's right, use port 587." =20
I can telnet to port 587, but actual use requires authentication with my
Comcast credentials. =20

I've reconfigure postfix for port 587 per=20
http://www.kclug.org/pipermail/kclug/2008-February/032558.html=20

and setup SMTP Authentication per=20
http://www.freelock.com/kb/postfix-relayhost=20
but I'm stuck on the last step:

     # urpmi --media main libsasl2-plug-login libsasl2-plug-plain
    bash: urpmi: command not found


Tony Yarusso gave me=20

> apt-get install libsasl2-modules   (That package will provide both
LOGIN and PLAIN.)

The install worked, but didn't provide the=20
urpmi command on Debian with postfix 2.3.8.

I've since moved to Ubuntu where apt-get says
libsasl2-modules is already the newest version.

If anyone can help, I would be glad to document the solution.
I'm running postfix 2.7.0 and can live with out-going mail only. =20