PMDF User's Guide
OpenVMS Edition

One very useful feature of PMDF MAIL is its ability to only display those message header lines which you want to see. You express your preferences with the SET HEADER_TRIMMING command and then save those preferences to the file PMDF_INIT:PMDF_MAIL_HEADERS.OPT with the /OUTPUT option of that command. Then, each time you run PMDF MAIL, only the header lines which you want to see will be displayed. On occasions when you do want to see the full header of a given message, use the /NOTRIM_HEADER qualifier which is accepted by all of the message reading commands. See the description of the SET HEADER_TRIMMING command for an example showing how to specify your own set of header trimming preferences.

While you might find it tempting to trim all but a very few header lines, it is strongly recommended that you always display (i.e., not trim) the following list of header lines: Bcc, Cc, Comments, Content-type, Date, From, Sender, Subject, To, Resent-Bcc, Resent-Cc, Resent-Date, Resent-From, Resent-Sender, and Resent-to. In practice, you often will not see many of these header lines. However, in those instances when they are present in a message header, it is important that you be aware of them. Take, for instance, the Sender: header line. It indicates who the authenticated sender of the message you are reading is. It is generally only present in the message header when it is not the same as the From: address. Why is this important? It tells you who really sent the message. If you had merely seen the From: line you might have been confused; especially if it is a piece of forged mail you are looking at.

PMDF_INIT is a logical which ordinarily points to your login directory. You can change the definition of this logical to point to another directory and then place your PMDF_MAIL_HEADERS.OPT file in the directory specified by the new definition of the logical.

Your system manager can also provide a PMDF_MAIL_HEADERS.OPT file which will be used should you not have one of your own. This file, which will be used system-wide by all users lacking their own, should be named PMDF_MAIL_HEADERS.OPT and kept in the PMDF_TABLE: directory. It should, of course, be world readable.