Please go through this link.
what is the difference between sender and properties of mailmessage class. How can we use both of these properties. Aren’t they same ?
Thanks for contacting us. I like to inform that from is the email address of the author(s)
while sender is address of the actual sender acting on behalf of the author listed in the From: field (secretary, list manager, etc.).
@Adnan.Ahmad,
Thank you. This means I should use information from From field to insert info in EmailOnBehalfOf and from “Sender” field to insert info in EmailFrom section ? Am I right ?