Not sure if this is possible, but I have a scenario that id like to fix by a script, here is the scenario
One mailbox sitting on an Exchange 2003 Server, the mailbox receives emails in the following format:
From: External@Contoso.com To: Internal@Domain.com Subject:UserX
UserX is anyone of 700 users at the company, we have five file servers i.e \\london\users\user1 \\portsmouth\users\user2 \\scotland\users\user3 \\wales\users\user4 \\newcastle\users\user5
Users My Documents are assigned via GPO, i.e London Users have there H drive mapped to the London File Server, Portsmouth Users have there H Drive mapped to the Portsmouth File Server.
Attachments are sent via email to one internal address from another external address, with the username who it is intended for in the subject.
What id like to do is create a script that pulls the username from the subject, queries 5 groups in AD i.e (London Users, Portsmouth Users, Wales Users, Scotland Users, Newcastle Users and depending where it finds the user place the file in the users my documents on that file server.
Sorry, didn't see the Exchange 2003 reference! Since you are running on a 10 year old version of Exchange, I'd say upgrading is a worthy project That said, Exchange 2010 is A LOT different then 2003, so study up before you go or get a good consultant.
But to make this work for Exchange 2003 you'll need to install Outlook and then use the Outlook ComObject to get the email. Should be plenty of examples on how to do this on Google.
It's been a very long time since I worked with PowerShell and Exchange 2003 and it looks like I've deleted my script archives from back then, so not much help from here. Hopefully, this you give you something to start with.