Avoiding duplicate/multiple redirected email messages.

[ArshadM]

Dear Sir,

I have Qmail installed in Control Panel Plesk 9 and Operating System Debian 4.0. I desire to know how to get only one copy of message instead of duplicate/multiple messages in a scenario such as the following redirected emails :-

purchase@domain.com redirect to xxx@domain.com
finance@domain.com redirect to xxx@domain.com
marketing@domain.com redirect to xxx@domain.com


If someone send email to purchase@domain.com with CC to finance@domain.com & marketing@domain.com the same email message at xxx@domain.com is received three times.

Is there any way to restrict to receive only one copy of the same message even if redirected from different accounts. Previously in sendmail the solution was available and all email accounts used to get only copy of the messages and multiple copies were able to avoid.

Regards.

Arshad.