500/Timeout when trying to send an email with my app?

Hello -

I'm kind of new to this whole web development thing - I have a VPS and
I've installed ubuntu 8.04 and postfix on it, and now I'm deploying
simple rails apps to get the hang of the whole process.

So I put together a small forum application, based on the
restful_authentication plugin. I've changed user_mailer.rb to reflect
the signup/activation emails that I want to send, but I haven't modified
restful_authentication beyond that - it's very basic and vanilla.

So I managed to use mod_rails to get my little app up and running - I
can see the empty forum and everything - but when I go to sign up as a
new user, I submit my information and the browser hangs for a short
while. Finally, it gives me the Rails 500 "We're sorry, but something
went wrong" screen.

The final entry in production.log is:

What method of sending mail are you using? Check your logs while you sen the mail.

Blog: http://random8.zenunit.com/
Learn rails: http://sensei.zenunit.com/

Sorry debt read enough of the mail. Badicall it's timing out when sending touour SMTP server. Are u sure the settings are right?

Blog: http://random8.zenunit.com/
Learn rails: http://sensei.zenunit.com/

Ah! All it needed was:

ActionMailer::Base.delivery_method = :sendmail

I was sure I was missing something obvious.

Thanks for your help!
Chris