Listlow,

I dont know if you have solved this or not, but i have just had to look into this and it is really simple.

In the EMC > Recipient configuration > mailbox

goto the properties of the user that you need to change, then the top line that has the user name in, change it to what you require, hit ok and job done.

When you send an email from that user you will now see the new display name. This will affect the address book!

Cheers

Stew