Received Line Information
Many optional fields:
from sending host
by receiving host
via physical path (predefined values)
with link/mail protocol (predefined values)
id reciever message id
for initial form
And one required field:
date-time timestamp when message received
Received: from CGNET.COM by Arizona.EDU (PMDF V4.3-9 #2381)
id HGUMM9OTUO9AR7DY@Arizona.EDU> Thu, 08 Sep 1994 00:39:13 -0700 (MST)