MH-MAIL(5)	   Headers, Tables, and	Macros	       MH-MAIL(5)

NAME
     mh-mail - message format for MH message system

SYNOPSIS
     any MH command

DESCRIPTION
     MH	processes messages in a	particular format.  It should  be
     noted  that  although neither Bell	nor Berkeley mailers pro-
     duce message files	in the format that  MH	prefers,  MH  can
     read message files	in that	antiquated format.

     Each user possesses a mail	drop box which initially receives
     all  messages processed by	post (8).  Inc (1) will	read from
     that drop box and incorporate the new messages  found  there
     into  the user's own mail folders (typically `+inbox').  The
     mail drop box 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 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, fol-
     lowed 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 MH, the header	and body may be	separated
     by	a line consisting of dashes:

	  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 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	(`:').	 Certain  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

[mh.6]		       Last change: MH.6.8			1

MH-MAIL(5)	   Headers, Tables, and	Macros	       MH-MAIL(5)

     "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    format    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)  sig-
     nals  that	 all  following	text up	to the end of the file is
     the body.	No formatting is expected or enforced within  the
     body.

     Following is a list of header components that are considered
     meaningful	to various MH programs.
     Date:
	  Added	by  post (8),  contains	 date  and  time  of  the
	  message's entry into the transport system.

     From:
	  Added	by post	(8), 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 present).

     Sender:
	  Added	by post	(8) 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:
	  Still	more recipients.  However, the "Bcc:" line is not
	  copied  onto	the  message as	delivered, so these reci-
	  pients are not listed.  MH uses an encapsulation method
	  for blind copies, see	send (1).

     Fcc:
	  Causes post (8) 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 (8)	if the `-
	  msgid' flag is set.

[mh.6]		       Last change: MH.6.8			2

MH-MAIL(5)	   Headers, Tables, and	Macros	       MH-MAIL(5)

     Subject:
	  Sender's commentary.	It is displayed	by scan	(1).

     In-Reply-To:
	  A commentary line added by repl (1) when replying to	a
	  message.

     Resent-Date:
	  Added	when redistributing a message by post (8).

     Resent-From:
	  Added	when redistributing a message by post (8).

     Resent-To:
	  New recipients for a message resent by dist (1).

     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	(8)  if	 the  `	-
	  msgid'  flag	is  set.   See "Message-Id:" and "Resent-
	  To:".

     Resent:
	  Annotation for dist (1) under	the `-annotate'	option.

     Forwarded:
	  Annotation for forw (1) under	the `-annotate'	option.

     Replied:
	  Annotation for repl (1) under	the `-annotate'	option.

FILES
     /var/mail/$USER			 Location of mail drop

PROFILE	COMPONENTS
     None

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

[mh.6]		       Last change: MH.6.8			3

MH-MAIL(5)	   Headers, Tables, and	Macros	       MH-MAIL(5)

DEFAULTS
     None

CONTEXT
     None

[mh.6]		       Last change: MH.6.8			4