2.1 Envelope-Part Structure

The Envelope-Part structure is the body text of the journal record message. The Envelope-Part structure contains metadata about the original message. The format of the Envelope-Part structure is specified by using the Augmented Backus-Naur Form (ABNF) notation, as specified in [RFC5234]. The format is a series of field/value pairs on CRLF-terminated lines. The format, prior to the application of any MIME encoding, is as follows.

 <Envelope-Part>           = <sender> CRLF
                             [<sent-on-behalf> CRLF]
                             (<subject> CRLF <message-id> CRLF) / (<message-id> CRLF <subject> CRLF)
                             [<label> CRLF]
                             [<mailbox-owner> CRLF]
                             [<sent-time> CRLF]
                             [<received-time> CRLF]
 <sender>                  = "Sender:" SP <reverse-path>
 <sent-on-behalf>          = "On-Behalf-Of:" SP <on-behalf-path>
 <subject>                 = "Subject:" SP <subject-string>
 <message-id>              = "Message-ID:" SP <msg-id>
 <label>                   = "Label:" SP 1*255CHAR
 <mailbox-owner>           = "Mailbox:" SP <mailbox-owner-address>
 <recipient-specification> = <recipient-p2-type> ":" SP <forward-path> 
                             ["," SP <redirection-type> ":" SP <original-forward-path>] CRLF
 <sent-time>               = "SentUtc:" SP <sent-time-string>
 <received-time>           = "ReceivedUtc:" SP <received-time-string>
 <recipient-p2-type>       = "Bcc" / "To" / "Cc" / "Recipient"
 <redirection-type>        = "Expanded" / "Forwarded"