We just noticed a issue appear with the way we are using contacts. The way we have the contacts setup now is like this:
Primary SMTP address: email@example.com
External E-mail address: firstname.lastname@example.org
This works just fine when one of our users sends to any contact. The issue comes up when one of our internal users sends to multiple contacts in the same email. If one of the contacts (contactA) does a reply to all it will try to reply to the other contact(contactB) with the email address email@example.com and this will bounce saying the user is not valid. If we set the primary smtp address to the be external address things seem to work fine.
My question is what is the correct way to setup a contact in exchange 2010? Should the primary address be the same as the external address?
We have a consultant saying that setting the primary address to an external address is wrong and breaks the way contacts work.
Please let me know if you need any additional information.