mh-mail(5mh)mh-mail(5mh)Namemh-mail - message format for MH message system
Description
MH processes messages in a particular format. Although neither Bell
nor Berkeley mailers produce message files in the format that MH
prefers, MH can read message files in that format.
Each user has a maildrop that initially receives all messages processed
by
The command reads from the maildrop and incorporates the new messages
found there into the user's own folder. The maildrop 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 in
ASCII 7-bit data.
The general memo framework of RFC 822 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 message header; the free-format portion is called the body.
The header must always exist, but the body is optional. These parts
are separated by a blank line or by a line of dashes. The following
example shows the standard default MH mail header:
To:
cc:
Subject:
--------
The header is composed of one or more header items. Each header item
can be viewed as a single logical line of ASCII characters. If the
text of a header item extends across several real lines, the continua‐
tion lines are indicated by leading spaces or tabs.
Each header item is called a component and is composed of a keyword or
name, along with associated text. The keyword begins at the left mar‐
gin, and is terminated by a colon (:). It cannot contain spaces or
tabs, and cannot exceed 63 characters, as specified by RFC 822.
The text for most formatted components, such as Date: and Message-Id:,
is produced automatically. The user enters address fields such as To:
and cc:, and the Subject: field. Internet addresses are assigned mail‐
box names and host computer specifications. The general format is
local@domain, for example, MH@UCI or MH@UCI-ICSA.ARPA. A comma (,)
separates multiple addresses. A missing host/domain is assumed to be
the local host/domain.
A blank line (or a line of dashes) signals that all following text up
to the end of the file is the body of the message. No formatting is
expected or enforced within the body.
The following is a list of header components that are considered mean‐
ingful to MH programs:
Date: Added by contains the date and time of the message's entry
into the transport system.
From: Added by contains the address of the author or authors (there
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 present.
Sender: Added by 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 the addresses of recipients who receive blind carbon
copies of the message. The Bcc: line does not appear on the
message as sent, so these recipients are not listed. Recipi‐
ents in the Bcc: field receive a copy of the message with a
minimal header. MH uses an encapsulation method for blind
copies; see
Fcc: Causes to copy the message into the specified folder for the
sender, if the message was successfully given to the trans‐
port system.
Message-ID:
A unique message identifier added by if the -msgid flag is
set.
Subject: Sender's commentary. It is displayed by
In-Reply-To:
A commentary line added by when replying to a message.
Resent-Date:
Added by when a message is re-distributed.
Resent-From:
Added by when a message is re-distributed.
Resent-To:
New recipients for a message re-sent by
Resent-cc:
New secondary recipients for a message re-sent by
Resent-Bcc:
New blind carbon copy recipients for a message re-sent by
Resent-Fcc:
Places a copy of a message re-sent by into the sender's
folder.
Resent-Message-Id:
A unique identifier of a message re-sent by This is appended
by if the -msgid flag is set.
Resent: Annotation added by when the -annotate option is specified.
Forwarded:
Annotation added by when the -annotate option is specified.
Replied: Annotation added by when the -annotate option is specified.
Files
Standard location of mail drop.
See Also
Standard for the Format of ARPA Internet Text Messages (RFC 822)
mh-mail(5mh)