MH-MAIL(5,F) AIX Technical Reference MH-MAIL(5,F)
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mh-mail
PURPOSE
The message format for the Message Handling (MH) Package.
DESCRIPTION
The Message Handling (MH) Package processes messages in a particular format.
While this format is different from that used by the Bell and Berkeley mail
systems, the MH package can read Bell and Berkeley message files.
Each user has a mail drop that initially receives all messages processed by the
post or spost command. The inc command reads from that mail drop and
incorporates the new messages found there into the user's own mail folder
(typically inbox). The mail drop consists of one or more messages.
Messages are expected to consist of lines of text. Graphics and binary data
are not handled. No data compression is accepted. All text is ASCII 7-bit
data.
The general memo framework of the ARPA Internet RFC 822 standard is used. A
message consists of a block of information in a rigid format, followed by
general text with no specified format. The rigidly formatted first part of a
message is called the header, and the free-format portion is called the body.
The header must always exist, but the body is optional. These parts are
separated by an empty line, that is, two consecutive new-line characters.
Within messages, the header and body may be separated by a line consisting of
dashes:
To:
cc:
Subject
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The header is composed of one or more header components. Each header component
can be viewed as a single logical line of ASCII characters. If the text of a
header component extends across several lines, the continuation lines are
indicated by leading spaces or tab characters.
Each header component is composed of a keyword or name, along with associated
text. The keyword begins at the left margin, may not contain space or tab
characters, may not exceed 63 characters, and ends with a : (colon). Certain
components (as identified by their keywords) must follow rigidly the defined
formats in their text portions.
The text for most formatted components (for example, "Date:" and "Message-Id:")
is produced automatically. The text for other components must be entered by
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MH-MAIL(5,F) AIX Technical Reference MH-MAIL(5,F)
the user (for example, "To:" and "cc:"). Multiple addresses are separated by
commas. A missing host/domain is assumed to be the local host domain.
HEADER COMPONENTS
Date: Added by post, spost, or the mail transport system;
contains the date and time of the message's entry into the
transport system.
From: Added by post or spost; contains the address of the author
or authors (may be more than one if a Sender field is
present). Replies are typically directed to addresses in
the Reply-To: or From: field (the former has precedence if
both are present).
Sender: Added by post or spost in the event that the message
already has a From: line. This line contains the address
of the actual sender. Replies are never sent to addresses
in the Sender: field.
To: Contains addresses of primary recipients.
cc: Contains addresses of secondary recipients
Bcc: Contains still more recipients. However, the Bcc: line is
not copied into the message as delivered, so these
recipients are not listed. The MH package uses an
encapsulation method for blind copies.
Fcc: Causes the post or spost command to copy the message into
the specified folder for the sender, if the message was
successfully given to the transport system.
Message-Id: A unique message identifier added by post or spost if the
-msgid flag is set.
Subject: Sender's commentary. It is displayed by the scan command.
In-Reply-To: A commentary line added by the repl command when replying
to a message.
Resent-Date: Added when redistributing a message by post or spost.
Resent-From: Added when redistributing a message by post or spost.
Resent-To: New recipients for a message resent by the dist command.
Resent-cc: More recipients. See cc: and Resent-To:.
Resent-Bcc: More recipients. See Bcc: and Resent-To:.
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MH-MAIL(5,F) AIX Technical Reference MH-MAIL(5,F)
Resent-Fcc: Copies resent message into a folder. See Fcc: and
Resent-To:.
Resent-Message-Id: A unique identifier attached by post or spost if you
specify the -msgid flag. See Message-Id: and Resent-To:.
Resent: Annotation that dist uses when you specify the -annotate
flag.
Forwarded: Annotation that the forw command uses when you specify the
-annotate flag.
Replied: Annotation that repl uses when you specify the -annotate
flag.
FILE
$HOME/.newmail Location of mail drop
RELATED INFORMATION
Standard for the Format of ARPA Internet Text Messages, RFC 822. See "Related
Network Publications."
The "Overview of the Message Handling Package" in Managing the AIX Operating
System.
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