In Exchange 2010, after several users reported failure notifications to internal mailboxes; I noticed that the address policy is automagically creating additional email addresses in the format of firstname.lastname@domain.com. Is there a way to change this behavior? -Other than just removing the additional smtp address and/or unchecking "automatically update email addresses based upon emal address policy"?

Exchange doesn't do anything on its own, so there must be an email address policy that does that. The default policy will be username @ so if your Windows user names are user.name then that would explain why email addresses are being created in that format. Everything is done through email address policy, so if you don't want to adjust every account manually, that is what you need to adjust. Simon. Simon Butler, Exchange MVP Blog | Exchange Resources | In the UK? Hire Me.