Got a situation with a single Exchange 2007 server, but happens with all users I try.
I've added a second public domain (also have a .local) to the "Accept Domains" field, and it's Authoritative. Let's say the domain is "MyDomain.com".
Then I added a SMTP address "userA@mydomain.com" to UserA's SMTP email address, but it's not his primary or "reply from" address, just another SMTP address. I also give UserA "Send As" permission to himself through EMC.
I open up their Outlook as UserA type in the From field "UserA@mydomain.com" and as soon as I hit send i get the famous "You do not have the permission to send the message on behalf of the specified user".
I did nothing with receipt policy. Do I need to?
This is a fresh install of Exchange 2007, not from 2000/2003/5.5.