New Post: PR_REDIRECTION_HISTORY vs PR_TRANSPORT_MESSAGE_HEADERS

Hello,

our exchange server allows for receiving mails sent to an 'alias' address. I don't know yet the correct exchange term of this feature, but effectively mails sent to this address are accessible in the primary message store.
To evaluate the alias address, I could parse the data of PR_TRANSPORT_MESSAGE_HEADERS:

...
Subject: test
From: external user <external.user@somewhere.com>
To: <aliased_adress@here.com> // <-- not <primary_address@here.com>
Content-Type: multipart/mixed; boundary="..."
Return-Path: external.user@somewhere.com
...

I'd rely on the "To: <e@d>" string containing the linked / aliased address. I don't know if this may be subject to change and therefore I am looking for an atomic property holding this information.

In MFCMAPI, I stumbled across PR_REDIRECTION_HISTORY. Looking into its value , I can see exactly the needed aliased address, surrounded by some binary data.
So my question is, what it this property about and how is the data held by it defined?

Thank you very much.