What is the difference between the ‘Send on Behalf” and “Send As” permissions on a mailbox?
Send on Behalf permission enables another user to send messages on behalf of the mailbox owner. Delegate’s name appears in the message. Send As permission is lot more serious as one user can send message and the recipient of that message would see as if the message has been sent by the original mailbox owner. Whereas the “Send on behalf” permission can be given from Client or the Administrator program, “Send As” permission can be given only be the administrator.
