Active Directory microsoft exchange groups

Question

If I add a user to more than one Active directory groups, and send an email to all of these groups, will the user get multiple emails (one per group) or just one email? Is Exchange clever enough to determine that it is the same user?

Answer 1

Exchange will only send the message one time, as long as the groups you're sending to are in the same organization. This may be an issue in very old versions of Exchange, but in 2007+ I know it suppresses duplicates.