Simple setup to forward (relay) mail on Ubuntu 10.04 LTS

The Basic Postfix Email Gateway on Ubuntu 10.04 guide is probably the way to go. In your case, since all mail is going to go off-site, you can probably omit the "Create Mail Directories" step. The "Sending Email Securely" section is also optional. (Postfix sendmail is easier to work with than Sendmail sendmail, in my experience.)

Thanks for the tip - I've already got sendmail running on my linode and quite a few rails apps are using that for sending out mail.

Seems like the postfix email virtual hosting is exactly the same as what I've detailed in my Gist, so I'll stick with sendmail for now. Thanks!