MH-MAIL(5)                                                           [nmh-1.5]                                                          MH-MAIL(5)

NAME

       mh-mail - message format for nmh message system

SYNOPSIS

       any nmh command

DESCRIPTION

       nmh processes messages in a particular format.  It should be noted that although neither Bell nor Berkeley mailers produce message files in
       the format that nmh prefers, nmh can read message files in that antiquated format.

       Each user possesses a mail drop box which initially receives all messages processed by post.  Inc will read from that drop box and incorpo-
       rate  the  new  messages found there into the user's own mail folders (typically "+inbox").  The mail drop box consists of one or more mes-
       sages.

       Messages are expected to consist of lines of text.  Graphics and binary data are not handled.  No data compression is accepted.   All  text
       is clear 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 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, i.e., two consecutive newline
       characters.  Within nmh , the header and body may be separated by a line consisting of dashes:

            From: Local Mailbox <user@example.com>
            To:
            cc:
            Fcc: +outbox
            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 continuation 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
       margin, may NOT contain spaces or tabs, may not exceed 63 characters (as specified by RFC-822), and is terminated by a colon  (`:').   Cer-
       tain components (as identified by their keywords) must follow rigidly defined formats in their text portions.

       The  text for most formatted components (e.g., "Date:" and "Message-Id:") is produced automatically.  The only ones entered by the user are
       address fields such as "To:", "cc:", etc.  Internet addresses are assigned mailbox names and host computer specifications.  The rough  for-
       mat  is  "local@domain",  such  as  "MH@UCI", or "MH@UCI-ICSA.ARPA".  Multiple addresses are separated by commas.  A missing host/domain is
       assumed to be the local host/domain.

       As mentioned above, a blank line (or a line of dashes) signals that all following text up to the end of the file is the body.   No  format-
       ting is expected or enforced within the body.

       Following is a list of header components that are considered meaningful to various nmh programs.

       Date:
            Added by post, contains date and time of the message's entry into the mail transport system.

       From:
            This  header  is  filled in by default with the system's idea of the user's local mailbox.  This can be changed with the Local-Mailbox
            profile entry.  It contains the address of the author or authors (may be more than one if a "Sender:" field is present).  For a  stan-
            dard  reply  (using  repl),  the  reply  address  is  constructed by checking the following headers (in this order): "Mail-Reply-To:",
            "Reply-To:", "From:", "Sender:".  A "From:" header MUST exist when the message  is  sent  to  post,  otherwise  the  message  will  be
            rejected.

       Mail-Reply-To:
            For  a  standard  reply  (using  repl),  the  reply  address  is constructed by checking the following headers (in this order): "Mail-
            Reply-To:", "Reply-To:", "From:", "Sender:".

       Mail-Followup-To:
            When making a "group" reply (using repl -group), any addresses in this field will take precedence, and no other reply address will  be
            added  to  the  draft.   If  this header is not available, then the return addresses will be constructed from the "Mail-Reply-To:", or
            "Reply-To:", or "From:", along with adding the addresses from the headers "To:", "cc:", as well as adding your personal address.

       Reply-To:
            For a standard reply (using repl), the reply address is constructed  by  checking  the  following  headers  (in  this  order):  "Mail-
            Reply-To:", "Reply-To:", "From:", "Sender:".

       Sender:
            Required  by  post  in  the  event  that the message has multiple addresses on the "From:" line.  It is otherwise optional.  This line
            should contain the address of the actual sender.

       To:
            Contains addresses of primary recipients.

       cc:
            Contains addresses of secondary recipients.

       Bcc:
            Still more recipients.  However, the "Bcc:" line is not copied onto the message as delivered, so these recipients are not listed.  nmh
            uses an encapsulation method for blind copies, see send(1).

       Dcc:
            Still  more recipients.  However, the "Dcc:" line is not copied onto the messages as delivered.  Recipients on the "Dcc:" line receive
            the same messsage as recipients on the "To:" and "cc:" lines.  See send(1) for more details.

       Fcc:
            Causes post to copy the message into the specified folder for the sender, if the message was successfully given to the transport  sys-
            tem.

       Message-ID:
            A unique message identifier added by post if the -msgid flag is set.

       Subject:
            Sender's commentary.  It is displayed by scan.

       In-Reply-To:
            A commentary line added by repl when replying to a message.

       Resent-Date:
            Added when redistributing a message by post.

       Resent-From:
            Added when redistributing a message by post.

       Resent-To:
            New recipients for a message resent by dist.

       Resent-cc:
            Still more recipients. See "cc:" and "Resent-To:".

       Resent-Bcc:
            Even more recipients. See "Bcc:" and "Resent-To:".

       Resent-Fcc:
            Copy resent message into a folder.  See "Fcc:" and "Resent-To:".

       Resent-Message-Id:
            A unique identifier glued on by post if the -msgid flag is set.  See "Message-Id:" and "Resent-To:".

       Resent:
            Annotation for dist under the -annotate option.

       Forwarded:
            Annotation for forw under the -annotate option.

       Replied:
            Annotation for repl under the -annotate option.

FILES

       /var/mail/$USER            Location of mail drop

SEE ALSO

       Standard for the Format of ARPA Internet Text Messages (RFC-822)

CONTEXT

       None

MH.6.8                                                             11 June 2012                                                         MH-MAIL(5)