1. Fire up “Active Directory Users & Computers”
2. Locate the user and look at the objects properties
3. In the Email Addresses tab - you’ll have a list of various entries. All of the ‘SMTP’ type are email addresses / aliases. The one in bold is the primary account.
4. To add a new alias: click New, select ‘SMTP address’, click OK and enter the desired email address.

Simples!
 

Did you find this hint useful? Are you looking to learn more about Exchange? Well, here’s a few books that I’ve found useful – have a goosie!

Microsoft Exchange Server 2003 Training kit

Mastering Microsoft Exchange Server 2003

Configuring Microsoft Exchange Server 2007 Training Kit

Microsoft Exchange Server 2007 for Dummies