Message.sender property (apps for Office)
Published: February 26, 2013
Gets the email address of the sender of an email message.
The from and sender properties return an EmailAddressDetails object that represents the same person unless the message is sent by a delegate. In that case, the from property returns the EmailAddressDetails object that represents the delegator, and the sender property represents the delegate.
When the client is Outlook 2013, the recipientType property of the EmailAddressDetails object is undefined.