Unable to get Exim4 to send emails to my own domain

OS: Debian6

Mailer: Exim4

Hostname: ahab

Hostname -f: ahab.MYDOMAIN.com

I followed this guide to set up Exim4: http://library.linode.com/email/exim/se … -6-squeeze">http://library.linode.com/email/exim/send-only-mta-debian-6-squeeze

Basically I want my server to send an email from my own domain to an email address with the same domain, which is on external mail exchanger. It can send to other domain names just fine… It just won't send mail to the same domain, like george@MYDOMAIN.com. it says that ahab.MYDOMAIN.com doesn't exist.

Here's the last few lines in my /var/log/exim4/mainlog

2012-05-24 12:04:22 1SXZaQ-0000cm-87 <= goomba@ahab.MYDOMAIN.com U=goomba P=local S=431
2012-05-24 12:04:22 1SXZaQ-0000cm-87 ** george@MYDOMAIN.com R=dnslookup T=remote_smtp: SMTP error from remote mail server after MAIL FROM: <goomba@ahab.mydomain.com>SIZE=1466: host mx.bellaliant.com [4.59.182.109]: 553 ahab.MYDOMAIN.com does not exist
2012-05-24 12:04:22 1SXZaQ-0000cp-I9 <= <> R=1SXZaQ-0000cm-87 U=Debian-exim P=local S=1433
2012-05-24 12:04:22 1SXZaQ-0000cm-87 Completed
2012-05-24 12:04:22 1SXZaQ-0000cp-I9 => goomba <goomba@ahab.mydomain.com>R=local_user T=maildir_home
2012-05-24 12:04:22 1SXZaQ-0000cp-I9 Completed</goomba@ahab.mydomain.com></goomba@ahab.mydomain.com> 

here is my MXLOOKUP

nslookup -sil -q=MX MYDOMAIN.com 2>&1
Server:         207.192.69.5
Address:        207.192.69.5#53

Non-authoritative answer:
MYDOMAIN.com  mail exchanger = 10 mx.bellaliant.com.

Authoritative answers can be found from:
MYDOMAIN.com  nameserver = ns1.meganameservers.com.
MYDOMAIN.com  nameserver = ns2.meganameservers.com.
MYDOMAIN.com  nameserver = ns3.meganameservers.com.

Please point me in the right direction for a solution. :)