Messages, being retrieved via POP3, are having their alias being replaced by its primary smtp address

Question

We use a CRM tool (Deerfield's VisNetic Mailflow) that POP's into Exchange 2007 to access their mailboxes.  Senders of email to this mailbox use one of many alias' assigned to the mailbox.  The issue we are having is that the alias (ie secondary address) is being replaced by the mailbox's primary address.
NB When I perform a test without POP'ing  (ie send\receive testing directly between a private external email address and my Exchange mailbox, back and forth), I am successful in retaining the secondary address.
Any idea what is causing the address to change from the alias (ie secondary) to the primary address when POP'ing?  POP does seem to be the variable here...just not sure what I should be looking at in order to fix this issue.
Regards,
Andrew

Answer 1

Following up on Andrew's post we're seeing some confirmation of a behaviour change in Exchange 2007:
Dear Colin,
Based on our lab test, it is confirmed that the behavior has changed in Exchange 2007. If a mail is received by Exchange 2007 store, the To field will remain as the intended recipient if you view the mail in Outlook 2003/2007. But the To header will always be changed to primary address if you view the mail in Windows Mail, Outlook Express via POP3 or IMAP. This is the reason that the same copy of a mail will exhibit the different address in header. In Exchange 2007, the real P2 address will be written to email to header only when it is transferred to MAPI format.
Below is the final test report in our lab
1: Exchange 2003 situation:
Mailbox Name: Test1, Test2.
Primary email address: [email protected], [email protected]
Secondary email address: [email protected], [email protected]
Use the Test1’s primary email address to send the message to its secondary email address and Test2’s secondary email address, then no matter which type of method we use to open these two mailboxes, the secondary email address will be listed in “to” field in this message’s message header. In the other word, the email address in the “to” field will not be changed to the recipient’s primary email address.
2: Exchange 2007 situation:
Mailbox Name: AA,BB.
Primary email address: [email protected], [email protected]
Secondary email address: [email protected], [email protected]
use aa’s primary email address to send the message to its secondary email address and bb’s secondary email address, then if we use pop3 method to open the message, then we will see the recipient’s Primary email address in the “to” field in this message’s message header. However, if open the message by using Outlook MAPI method, then the recipient’s secondary email address in the “to” field in the message’s message header.
In Exchange 2003 , if send the message to recipient’s secondary email address, then this secondary email address will be shown in the message’s message header without any change.
However in Exchange 2007 situation, once you send the message to the recipient’s secondary email address, then open and view this message’s message header by Outlook MAPI, then the recipient’s secondary email address will still be shown in the “to” field. If we open and view this message’s message header by the POP3 or IMAP method, then the recipient’s primary email address will be shown in the “to” field in Message header instead of its secondary email address. This behavior is the new change in Exchange 2007 situation.
Meanwhile, I have reviewed your replies again and I know that we open the message to your tickets message from the General delivery mailbox using Windows Mail on Vista and an IMAP connection. However, you opened the message to your person mailbox using Outlook 2007 on Vista using a MAPI connection. Hence, we will encounter two different behavior in “to” list in the message header.
I understand that the VisNetic MailFlow application is probably a critical application in your organization. However, it seems this application work with POP3 or IMAP4 method. If so, it may not be able to get the secondary email address in the message’s message header. I am wondering if there is a MAPI versions of this utility so that it can recognize the original header.
I hope my explanation can clarify this issue more explicitly. If you have any question about my explanation, please let me know.
Thanks.
Best regards,
Jeff Zeng
Microsoft Messaging Support Service