On Thu, Jun 15, 2006 at 02:34:20PM -0400, Matthew Gracie wrote:
> I'm not saying that port 25 incoming would be blocked on my local
> machine. Rather, I have seen ISP configured so as to block port 25
> traffic outward from an end user to anything _except_ the ISP's
> sanctioned mail server. This is pretty common in some home broadband
> networks as an anti-spam measure, to keep compromised hosts from sending
> mail.

In that case, you can configure the MTA on your local machine to relay
all mail through the ISP's sanctioned mail server.  In postfix this is
set in /etc/postfix/main.cf on a line like
relayhost = mailserver.isp.tld

mail/msmtp may be simpler

Ben