How can I set multiple default signatures when using Outlook/Exchange Server 2003?

Hi,

I have Exchange Server 2003 running as an email server.  We have an employee who uses Outlook 2003 to connect to two separate mailboxes - mailbox A and mailbox B.  When sending emails from these accounts, different signatures are required.  The user has set up 2 unique signatures and is able to manually choose a signature depending on which account the mail is being sent from.  But what they would really like is if each mailbox can be linked to different default signatures.  This would mean that the signature selection process would be automeated.

I expected that this would be possible by going to Tools/Options/Mail Format/Signatures, but when you go here there is just one account listed in the drop down box.  The account listed is 'Microsoft Exchange Server'.

This seems like something that lots of people would want and that wouldn't be very hard to program so I'm hoping that there is a way to achieve this.

Thanks for your help with this!