[NCLUG] using smtp

[rosing at peakfive.com]

I had some mail bounced because the machine I sent to didn't like my
domain:

 (reason: 550 This domain (client.attbi.com) is banned, contact your local admin.

So I changed emacs to run my outgoing mail through mail.frii.com and
that fixes it. But now trestlemail, which I use to distribute mail to
other people that shows up on my machine, doesn't know about using
this.  Is there a better way to specify the smtp machine?  Sendmail
doesn't seem to have any options for this.

Thanks,

Matt