You use recipient policies to control email address-generation for an Exchange organization. To add a new SMTP address, perform these steps:

1. Start Exchange System Manager (ESM).
2. Expand the Recipients container in the navigation pane and select Recipient Policies.
3. Right-click Default Policy in the details pane and select Properties.
4. Select the E-Mail Addresses (Policy) tab.
5. Click New.
6. Select the address type (e.g., SMTP Address) from the displayed dialog box and click OK.
7. Enter the new address. The default format for entering the address is

user_name@domain_name.com

but you can use control characters to control how the unique part of the name (i.e., user_name) will be generated. These are the control characters you can use:

• %s–surname (last name)
• %g–given name (first name)
• %I–middle initial
• %d–display name
• %m–Exchange 2003 alias
• %rxy–Replace all subsequent characters x with character y in username. If x = y, the character will be deleted.

Additionally if you add a number between the % and the character, it will use that number of characters (e.g., %1g will use only the initial of the first name).
8. Click OK.

Select the checkbox next to the new address to enable it and ensure it’s generated for all users. If you want the new SMTP address to be the primary address, select the new entry and click Set as Primary