[Dovecot] Issue with domains

I am running Dovecot 1.0.10 and have it working great on ender.ath.cx (my free DynDNS.com subdomain), but recently I registered lemcoe.com and pointed it to the same IP address as ender.ath.cx. The problem is, only e-mail sent to the @ender.ath.cx works. If it is send it to @lemcoe.com, I don't know where it goes. I get no errors either.

How can I get Dovecot to recognize both domains?

TIA.

David