When a message is sent to a moderated mailing list, the
Date: header of that message is set by the email program of the person sending
the message.
However, if the message is approved
at a later date, it is often best to have the Date: header of the message
reflect the date when the message was sent by Lyris, rather than the authored
date.
This setting sets the default for
moderated messages to automatically rewrite moderated Date headers. You can
still choose to rewrite (or not) the Date headers of individual moderated
messages by using the moderated message web interface menu, and affecting
individual messages.