User Sending as Multiple Email Addresses

Many organizations want a single user to have multiple email addresses and would like the user to be able to select which email address to send as. In Exchange 2010 (and earlier versions) it's very easy to add multiple email addresses for a user. However, the sending is a problem.

When multiple email addresses have been configured for a user, only one email address can be set as the primary/Reply To address. The primary address is the From address when sending a message. The user cannot select an alternate From address from their list of addresses.

You can buy commercial software that enables this functionality (http://www.ivasoft.biz/choosefrom2007.shtml). However, for the cheap (ahem, cost sensitive) among us there is a workaround.

1. For any secondary address you want to assign to a user, create a distribution group with that address.
2. Make the user the only member of that group.
3. Assign the user Send As permission for the group.

It's not very scalable, but easy to do.