106 lines
4.0 KiB
Plaintext
106 lines
4.0 KiB
Plaintext
.\" $NetBSD: mail7.nr,v 1.3 2003/08/07 11:14:45 agc Exp $
|
|
.\"
|
|
.\" Copyright (c) 1980, 1993
|
|
.\" The Regents of the University of California. All rights reserved.
|
|
.\"
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
.\" modification, are permitted provided that the following conditions
|
|
.\" are met:
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer.
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer in the
|
|
.\" documentation and/or other materials provided with the distribution.
|
|
.\" 3. Neither the name of the University nor the names of its contributors
|
|
.\" may be used to endorse or promote products derived from this software
|
|
.\" without specific prior written permission.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
|
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
|
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
.\" SUCH DAMAGE.
|
|
.\"
|
|
.\" @(#)mail7.nr 8.1 (Berkeley) 6/8/93
|
|
.\"
|
|
.sh 1 "Format of messages"
|
|
.pp
|
|
This section describes the format of messages.
|
|
Messages begin with a
|
|
.i from
|
|
line, which consists of the word
|
|
.q From
|
|
followed by a user name, followed by anything, followed by
|
|
a date in the format returned by the
|
|
.i ctime
|
|
library routine described in section 3 of the Unix Programmer's
|
|
Manual. A possible
|
|
.i ctime
|
|
format date is:
|
|
.(l
|
|
Tue Dec 1 10:58:23 1981
|
|
.)l
|
|
The
|
|
.i ctime
|
|
date may be optionally followed by a single space and a
|
|
time zone indication, which
|
|
should be three capital letters, such as PDT.
|
|
.pp
|
|
Following the
|
|
.i from
|
|
line are zero or more
|
|
.i "header field"
|
|
lines.
|
|
Each header field line is of the form:
|
|
.(l
|
|
name: information
|
|
.)l
|
|
.i Name
|
|
can be anything, but only certain header fields are recognized as
|
|
having any meaning. The recognized header fields are:
|
|
.i article-id ,
|
|
.i bcc ,
|
|
.i cc ,
|
|
.i from ,
|
|
.i reply-to ,
|
|
.i sender ,
|
|
.i subject ,
|
|
and
|
|
.i to .
|
|
Other header fields are also significant to other systems; see,
|
|
for example, the current Arpanet message standard for much more
|
|
information on this topic.
|
|
A header field can be continued onto following lines by making the
|
|
first character on the following line a space or tab character.
|
|
.pp
|
|
If any headers are present, they must be followed by a blank line.
|
|
The part that follows is called the
|
|
.i body
|
|
of the message, and must be ASCII text, not containing null characters.
|
|
Each line in the message body must be no longer than 512 characters and
|
|
terminated with an ASCII newline character.
|
|
If binary data must be passed through the mail system, it is suggested
|
|
that this data be encoded in a system which encodes six bits into
|
|
a printable character (i.e.: uuencode).
|
|
For example, one could use the upper and lower case letters, the digits,
|
|
and the characters comma and period to make up the 64 characters.
|
|
Then, one can send a 16-bit binary number
|
|
as three characters. These characters should be packed into lines,
|
|
preferably lines about 70 characters long as long lines are transmitted
|
|
more efficiently.
|
|
.pp
|
|
The message delivery system always adds a blank line to the end of
|
|
each message. This blank line must not be deleted.
|
|
.pp
|
|
The UUCP message delivery system sometimes adds a blank line to
|
|
the end of a message each time it is forwarded through a machine.
|
|
.pp
|
|
It should be noted that some network transport protocols enforce
|
|
limits to the lengths of messages.
|