Delegated sender: auditability

[chibenwa]

GIVEN Bob sends a Mail (JMAP/IMAP)
THEN a Sender header is positionned on the email with the logged in user that performed the action

How?

• Mailet DelegatedSenderAuditability

Uses mail metadata org.apache.james.jmap.send.MailMetaData.username and org.apache.james.SMTPAuthUser to populate the Sender header if it is different from the MAIL FROM field.

[chibenwa]

To be functionally discussed as James keeps track of the sender. We could add option to send on behalf of and handle Sender header display in the front.
We might want to keep track of the loggedInUser in the mailet container too.