Email diversion question

Hi

Please can someone help with the following problem: I run a server with Small Business Server 2000 (SBS) and Exchange 2003. I have set up several users and each has their own email box eg. user1@company.com. On one of the user's I wish to temporarily set up "email diversion" so if anyone sends an email to say joe_bloggs@company.com (i.e the user's normal email address) it gets automatically forwarded to another specified destination instead.

I've managed to do this fine in the past by creating a contact in SBS which acts as the new destination SMTP address. I then save and close the contact I've just created. Then in the User's properties I go to the "Exchange General" tab and then go to "Delivery Options" and select "Forward To:" and select the "contact" as the destination address.

This is fairly straight forward and has always worked fine in the past. However for some reason it is not working now. If I send an email from another user (i.e example_user@company.com) on the server to joe_bloggs@company.com it gets automatically forwarded to the new destination address fine. However if I try to send an email from an external email address, for example Yahoo.com the mail never arrives - it doesn't seem to arrive anywhere, not on joe_bloggs' normal email and nor does it appear in the specified new destination address - and no returned error occurs. This is quite strange as I currently have email diversions set up with a couple of other users and these work fine as I tested them today. Although this latest attempt does not work and I tried creating a second test email diversion and this doesn't work either.

Please can anyone shed light on this problem, and what might be the cause?

Thank you very much for any help or information.

Matt