Technical data

Configuring and Managing the POP Server
18.1 Key Concepts
18.1.6 Understanding POP Message Headers
Mail message headers sent by the POP server must conform to the standard
specified for SMTP in RFC 822. Because many of the messages received on an
OpenVMS system are not in the SMTP format (for example, DECnet mail or
mail from another message transport system), the POP server builds a new set of
headers for each message based on the OpenVMS message headers.
The headers on mail messages forwarded by the POP server are as follows:
POP Message Header Obtained From
Date: Arrival date of message. Changed to UNIX format.
From: OpenVMS message From: field. Rebuilt to ensure RFC 822
compatibility. See Section 18.1.6.1.
To: OpenVMS Mail To: field. Not rebuilt.
CC: OpenVMS Mail CC: field. Not rebuilt.
Subject: OpenVMS Mail Subj: field. Not rebuilt.
X-VMS-From: OpenVMS Mail From: field. Not rebuilt.
X-POP3-Server: Server host name and POP version information. Sent only if
logical name TCPIP$POP_SEND_ID_HEADERS is defined.
X-POP3-ID:
Message UID. Sent only if logical name
TCPIP$POP_SEND_ID_HEADERS is defined.
The POP server sends these message headers to the POP client unless all of the
following conditions are true:
• The TCPIP$POP_IGNORE_MAIL11_HEADERS logical name is defined (see
Section 18.3).
• The
From: address is an SMTP address.
• The SMTP qualifier /OPTION=TOP_HEADERS is set.
Note that the POP server checks the SMTP configuration database to ensure
that it has been configured with the qualifier /OPTION=TOP_HEADERS so that
headers print at the top of the message. If the POP logical name TCPIP$POP_
IGNORE_MAIL11_HEADERS is defined, the SMTP option TOP_HEADERS must
also be set. If not, the POP server issues a warning in the log file and does not
acknowledge the TCPIP$POP_IGNORE_MAIL11_HEADERS definition.
18.1.6.1 How POP Rebuilds the OpenVMS Mail From: Field
The most important message header is the
From: header, because it can be used
as a destination address if a reply is requested from the POP client. Therefore,
the POP server rebuilds the OpenVMS Mail From: field in compliance with RFC
822 before sending the header to the POP client.
The different types of addresses that can appear in the OpenVMS Mail
From:
field are as follows:
18–4 Configuring and Managing the POP Server