To understand my problem, I must first describe my setup and intentions.
I'm currently trying to setup journaling to a cloud based archive vendor. In order to do this, I must use a mail enabled contact for my journaling rule email@example.com (My normal mail domain is contoso.com, and journal.contoso.com is a non-routable domain).
In conjunction with the mail enabled contact, I have a send connector setup to route any mail destined for *@journal.contoso.com to our smarthost, archiving.smarthost.com.
Currently, we are sending journaled mail to the smarthost just fine. The problem is, some of these messages don't display the From Address correctly, they just show up as <>.
Upon further inspection, I determined that this is occurring in our queue viewer, and is not on the smarthosts end.
Here's where it gets weird. Exchange only does this with external email addresses, not internal, and it doesn't do it to all external address either; some of them show up just fine. On the messages missing the from field, I have verified that they are legit messages, not SPAM. I can see no difference between the messages where Exchange strips the From Address, and the ones where Exchange leaves it alone.
Currently, I have two servers running HT & CAS roles, two Edge servers, and a mailbox cluster.
Any ideas at all? It is greatly appreciated.