How to set Send As permissions on Exchange 2003
Sunday, March 5th, 2006This KB327000 explains how to set the “Send As” permission, but when you want to test it immediate after you changed the permissions chances are that it does not work. The Exchange Information store service caches this information for 120 minutes (the standard value). If you cannot wait that long, then you can restart the Information store service.
If you want to change the time that this information is cached then look at KB327378.