no idea why but gmail seems to be blocking / swallowing emails that are sent from a gmail account to itself via a forward.

i had the same issue when setting up exim for mail forwarding on my linode. i sent a msg to xxx@mydomain.com and was expecting it to come back into my inbox but it never did.
then i sent one from another email address and it all went fine.

pretty annoying when you want to test stuff...

What's really weird is this only started when I switched from sendmail to postfix.

This makes me think whether the problem is on Gmail's side or not.

Thanks for the help guys.

I've ended up writing the script from scratch and noticed a few boundary value problems. Some mail clients don't care about it (that's why they got delivered to my non-gmail address) but gmail swallows it.

Marking the thread as solved.