Exchange Server ID

I am using gpgol w/Outlook 2003 and WinPT and MS Exchange. When I try to send an encrypted email to a co-worker, it cannot find the public key to which the message should be encrypted because the ID it’s trying to use is an “Exchange Server ID” that looks very much like an LDAP reference. Here is a sample:


The above is in the “Recipient Dialog” window, in the “Recipient which were NOT found” box. I dug around and found a comment that PGP (5?) had been enhanced to automatically add the “Exchange server ID” to the userid for the public key. When I try to add this ID to my public key I get “Invalid email” and it won’t let me do it. Is this a bug? Or, perhaps I should say, “a missing feature?”