19Feb/10Off
SendAs right using Exchange shell
Link: http://exchangepedia.com/blog/2007/03/how-to-assign-sendas-right-using.html
You can use the Exchange shell to assign SendAs right (e.g. on a Distribution Group) to a user:
Add-AdPermission "Group Name" -user "User Name" -AccessRights
extendedright -ExtendedRights "send as"