Sending /Receiving Email Help!

I’m having this problem.

I’m on CentOS 5.2
Postfix
Dovecote IMAP/POP3

When sending email through gmail, I get this error:

The mail system

<ashier-xxx.xxx@localdomain.localdomain> (expanded from
<ashier@xxx.xxx>): Host or domain name not found. Name service
error for name=localdomain.localdomain type=A: Host not found

Final-Recipient: rfc822; ashier-xxx.xxx@localdomain.localdomain
Original-Recipient: rfc822;ashier@xxx.xxx
Action: failed
Status: 5.4.4
Diagnostic-Code: X-Postfix; Host or domain name not found. Name service error
for name=localdomain.localdomain type=A: Host not found

I have installed squirrelmail and I can send email through that, but I can’t receive any emails.

What should I do? Please help…

nevermind… I got it working…