I often work with the HMC hosting team when weird OAB generation problems come about. This request was a bit different that normal. There was a hosting customer out there that wanted to be able to forward emails to another account that were not in their hosting domain but did not want to create a mail-enabled contact to get this to work.
For common knowledge we know recipient policies are using for incoming email routing, amongst other things. For Exchange 2003, if you use the ESM and go to the Exchange General Tab and select delivery options you can specify an alternate recipient. If you do this it will set the altRecipient attribute on the user and populate the DN of that object specified. When we send an email we will bind to that DN and read the necessary attributes off of the altRecipient account so we can send the email outbound.
Trying to set the fowardingAddress (which is not supported) will not work. Most people set the prefix of a proxy address which is not correct. See below for an example:
fowardingAddress = must also contain the DN of an object, not the suffix like SMTP:firstname.lastname@example.org. This is not supported nor will work
targetAddress = must also contain the DN and so forth.
With all of this testing Fauzia Awan from the HMC team was able to come up with a solution to this problem.
All those folks using Exchange 2003 out there who do not want to make mail enabled contact for each external recipient that you want to set as forwarding address on a user’s mailbox.. this might come in handy:
This assumes you already have an Internet SMTP connector with SMTP address space space *
1. In Exchange System Manger Select Allow Automatic forward checkbox on Global Settings->Internet Message Format ->Default->Properties>Advanced
2. Using ADSI Edit connect to Schema and then navigate to Schema attribute ms-Exch-Forwarding-Address properties and set isMemberOfPartialAttributeSet to True
3. Now using ADSiEdit set forwardingAddress attribute on mailbox user’s properties to the external recipient address to which you want the mail forwarded (for example email@example.com)
I want to thank Fauzia Awan and Mohammed Qassim from the HMC team for coming up with this workaround for everybody!!
NOTE: Please be advised that this will not work on Exchange 2007!