The problem, I guess, is that if there is a "standard" port for SMTP (25) and a "standard alternative" port for SMTP (587), then ISPs are going to start blocking both.
This is a common misconception, but just the opposite is true: port 587
is intentionally intended to be left open when port 25 is blocked. Port
587 must be configured to only accept authenticated outgoing mail from
users known to the system -- it does not accept unauthenticated incoming
mail, so it can't be used for spam.
Fine. But I'm at home and I want to send mail through a different mail server, instead of Sympatico. However, Sympatico blocks outbound port 25 traffic from my DSL connection.
My ability to send it to port 587 of the different mailserver relies a) on Sympatico not blocking outbound 587 traffic (which probably won't happen), AND b) my different mailserver listening on port 587 for my connections.
It's the second part of that equation where the problem lies. It's not configuring your client to send on port 587, it's getting your receiving mailservers to start listening on port 587.
- Colin
