For Distribution Group in Exchange Server 2003, you can configure the message restrictions to accept messages only from the specified user/group. I would like to know the message restrictions can only work for Security Group only or Distribution Group only. What I mean is if I have Distribution List A and I want to configure it to receive only email from Distribution List B and Security Group C, will it work for C or it only work for B?

Affendi, You have two Distribution List Named DIST-A, DIST-B and one mail enabled security group named SEC-C. After that you have configured your DIST-A to accept mails from only DIST-B and SEC-C. If that is the case only DIST-B and SEC-C users can able to send mails to DIST-A. Yes, if your security group is a mail enabled one, then definitely it should work. Thanks, SanthoshSanthosh Sivaraman MCITP: Microsoft Exchange Server 2007/2010 | MCSE/MCSA