SBS Exchange send as a distrubutions group

You need to grant the users the "Send As" permissions. Not sure how to accomplish that on SBS 2003, but on Exchange 2003 or 2007 you will:

1. Start the Exchange version of Active Directory Users and Computers
2. From the View menu choose Advanced Features.(Must activate this option to see the Security tab after Properties)
3. Right click the user who wants to let other people send messages on his behalf and select Properties.
4. Select the Security tab and click Advanced.
5. Select the Permissions tab and click Add.
6. Enter the users who require the Send As permission, then click OK.
7. You will see the list of permissions. Make sure that "This object only" is selected for the apply field, then scroll to the bottom and select the Send As permission. Click OK.
8. OK the Advanced security dialog box, and OK the User Properties window to close.