Postfix SMTP sends to localhost, ignores MX records set to Google Apps

I have the MX records for zaltin.com set to the Google Apps domains (aspmx.l.google.com etc.). If an email is sent to [email protected] from most places, it goes to my Google Apps account. However, on the zaltin.com server (Ubuntu 10.04 if it matters), sending via SMTP (postfix), if I send to [email protected] (via the Pony ruby gem if it matters), it simply routes to kerrick@localhost (showing up via the mail command) instead of going to my Google Apps account (where it should show up in my GApps Gmail inbox).

Can I make email sent via SMTP on my server, through my server, not go to my server but to Google Apps?

You either have an entry in /etc/hosts pointing zaltin.com to localhost, like this:

127.0.0.1   zaltin.com

In which case you need to remove this, or you've configured Postfix to treate zaltin.com as a local destination in /etc/postfix/main.cf like this:

mydestination = localhost, zaltin.com

In which case you need to remove this.