Postfix using wrong email addresses

I logged into the new server as ezms via roundcube.
I sent a test email message to ezom@ez-om.com which is also on this server.

Postfix seems to be rewriting the To address to ezom@ezms1.ez-merchant-hosting.com rather than simply leaving the address alone and delivering it to ezom@ez-om.com.

Can you help me figure out my configuration problem?

thanks,
tony

Maillog output for this is:

Jan 18 16:38:01 ezms1 dovecot: imap-login: Login: user=, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, secured
Jan 18 16:38:01 ezms1 postfix/smtpd[1739]: connect from localhost[127.0.0.1]
Jan 18 16:38:01 ezms1 postfix/smtpd[1739]: 3A6242D282BF: client=localhost[127.0.0.1], sasl_method=LOGIN, sasl_username=ezms@ezms1.ez-merchant-hosting.com
Jan 18 16:38:01 ezms1 postfix/cleanup[1742]: 3A6242D282BF: message-id=<7dd1dddb604c5deeb8ba5361d80e56d1@tools.ez-ms.com>
Jan 18 16:38:01 ezms1 postfix/qmgr[2447]: 3A6242D282BF: from=, size=539, nrcpt=1 (queue active)
Jan 18 16:38:01 ezms1 dovecot: IMAP(ezms): Disconnected: Logged out
Jan 18 16:38:01 ezms1 postfix/smtp[1743]: 3A6242D282BF: to=, orig_to=, relay=none, delay=0.07, delays=0.02/0.01/0.04/0, dsn=5.4.6, status=bounced (mail for ezms1.ez-merchant-hosting.com loops back to myself)
Jan 18 16:38:01 ezms1 postfix/cleanup[1742]: 4EC8C2D282E4: message-id=<20090119003801.4EC8C2D282E4@ezms1.ez-merchant-hosting.com>
Jan 18 16:38:01 ezms1 postfix/smtpd[1739]: disconnect from localhost[127.0.0.1]

Status: 
Closed (fixed)