Thanks Aaron! Your suggestion turns out to be the problem. I was sending my tests from gmail, though I was using a different account than my gmail account for the from address. Apparently, gmail doesn't like that. Sending from that same address but using a different mail client, the mail goes to my inbox.
Looks like my postfix configuration was fine ;-) Though I went ahead and also setup a SPF record in the DNS for all my hosted domains. Seemed like a smart thing to do. -- ryan
