Really hope someone has a solution to this problem. Email process in plesk (qmail) will be tagged with a number just before the email address in the email header. Example: Return-Path: <email@example.com> Delivered-To: firstname.lastname@example.org Received: (qmail 18295 invoked by uid 110); 18 May 2004 04:39:24 -0000 Delivered-To: email@example.com Where "firstname.lastname@example.org" is the catch-all box. Then a POP3 downloader will collect email from the plesk server to deliver email to the exchange server. Problems: 1) When someone BCC to a user of abc.com.sg, an error of "NO VALID RECIPIENTS FOR MESSAGE" occur. 2) Same problem when someone send to a mailing list, where a user of abc.com.sg is in the list. No problem when To: & CC: field has a valid email address of the recipients. So the tagging of a number before the email address in the email header become an invalid email address when it reach another email server like exchange server, thus resulted in mail delivery error. I looked at the virtualdomains file and it is listed in therer a Domain:8 I tried to remove the domain and add it to the locals file and it did not work. Anyone has any clue how to fix this.