When you read a message, you see a long set of header fields above the actual text of the message. You can decide which ones you want to see by setting one or more variables.
A simple message might look like this when you read it:
Message 73 (378 chars) Return-Path: <jb51> Received: by cunixf.cc.columbia.edu (5.59/FCB) id AA01344; Monday, 7 Sep 92 10:50:29 EDT Date: Monday, 7 Sep 92 10:50:28 EDT From: Joe Brennan <email@example.com> To: fb2 Cc: mm33, hk12 Subject: Meeting on Sept 21 Message-Id: <CMM.firstname.lastname@example.org> Let's meet on Sept 21 at 2:00 to go over plans for this semester. Joe
The header fields Received and Message-Id are usually not very interesting. This is not even a bad case. Some messages have so many header fields that the message text doesn't even start on the first screen.
You can hide some of the fields by using the variables dont-type-headers and only-type-headers. The word type is used here in a sense found often in computing: to type is to display on screen. (The MS-DOS command type uses this meaning.)
Use only one of the two variables. With dont-type-headers, name the fields you don't want to see. With only-type-headers, name the fields you do want to see. Usually dont is a shorter list.
The following setting of dont-type-headers improves the appearance of messages by hiding the least interesting fields:
MM>set dont-type-headers received, return-path, message-id, resent-message-id) MM>save-init
The fields received, message-id and return-path are visible in the earlier example. (Capitalization is not important here.) The line return-path shows details of mail delivery, but other fields like from or reply-to show more generally useful information. The field resent-message-id results from forwarding and is no more interesting than message-id.
After the above setting of dont-type-headers, the same message will appear as follows:
Message 73 (378 chars) Date: Monday, 7 Sep 92 10:50:28 EDT From: Joe Brennan <email@example.com> To: fb2 Cc: mm33, hk12 Subject: Meeting on Sept 21 Let's meet on Sept 21 at 2:00 to go over plans for this semester. Joe
That looks much cleaner, and the remaining header fields are actually interesting information about the message.
At times, you may actually want to see all the header fields. Rather than reset the variable temporarily, use the command literal type. The prefix literal means to do a type command ignoring any settings of dont-type-headers or only-type-headers.
Showing just the beginning of each display, the difference is:
MM>type 73 Message 73 (378 chars) Date: Monday, 7 Sep 92 10:50:28 EDT From: Joe Brennan <firstname.lastname@example.org> To: fb2 ...
MM>literal type 73 Message 73 (378 char