Same Message ID Issue   

Dear Sir,

I've a question about one user belong to two mailing group.

When I sent a email to that two mailing group, that user always receive only 
one email message. 

Why? how can I do for this issue? (Want to receive two messages)

Regards,
Kit.

date: Wed, 26 Sep 2007 19:48:01 -0700   author:   TK LEUNG