I also can't recieve e-mails to my main account, but I can to my GMail account...
I wasn't able to confirm surfi's problem with the missing line breaks... they work fine for me (at least when viewed in GMail).
I'll look into it some more...
Surfi, can you configure the mailer to send a valid Return-Path header? It's currently nobody@srv06, and srv06 isn't a valid domain name. I tried setting the header with PHP, but it gets overridden.