I have windows 2008 with smtp enabled. I merely want to send sharepoint alerts out to email addresses external to the network but I have a dynamic comcast ip address. So to avoid blacklisting, I want to relay my smtp outgoing mail to comcast's email server using my comcast credentials and have them send my email out.
It seems as though I'm supposed to use port 465 or 587 if necessary, but not port 25 as they block outgoing transmissions using port 25.
How do I set my smtp server to relay over port 465 or 587?
In my advanced outgoing settings, I have my smtp server's name as the FQDN (machinename.domain.com). I have set it to not try and send mail itself and have set the smart host address to mail.comcast.net. On my router, under port forwarding I opened up ports 465 and 587. To get it to send it to the smarthost using port 465 (comcast recommended), I tried making the smarthost address mail.comcast.net:465, but anytime I add a port number it tells me invalid domain name.