setforward(1)						      General Commands Manual						     setforward(1)

NAME

       setforward - create a forwarding database

SYNOPSIS

       setforward cdb tmp

DESCRIPTION

       setforward  reads  a table of forwarding instructions from its standard input.  It converts the table into a forwarding database.  The for-
       warding database can be used by fastforward.

       setforward writes the forwarding database to tmp; it then moves tmp to cdb.  tmp and cdb must be on the same filesystem.

       If there is a problem creating tmp, setforward complains and leaves cdb alone.

       The forwarding database format is portable across machines.

INSTRUCTION FORMAT

       A forwarding instruction contains a target, a colon, a series of commands, and a semicolon.  Each command is  a	recipient  address,  owner
       address, external mailing list, or program.  Commands are separated by commas.

       For example,

	  root@yp.to: god@heaven.af.mil, staff@af.mil;

       says that mail for root@yp.to should be forwarded to the recipient addresses god@heaven.af.mil and staff@af.mil.

       When setforward sees # it ignores all text from # to the end of the line:

	  # this is a comment

       setforward  ignores  all  other	line  endings,	so  you can split a forwarding instruction across lines.  It also ignores spaces and tabs.
       Exception: you can put a space (or tab or comma or whatever) into a target or command by putting a backslash in front of it.  (However, NUL
       bytes are not permitted anywhere.)

TARGETS

       When  fastforward  sees the incoming address user@host.dom, it tries three targets: user@host.dom, @host.dom, and user@.  It obeys the com-
       mands for the first target that it finds.  Target names are interpreted without regard to case.

       All the commands for a single target must be listed in a single instruction.  Exception: an owner address  can  be  listed  in  a  separate
       instruction.

RECIPIENT ADDRESSES

       If a command begins with an ampersand, setforward takes the remaining bytes in the command as a recipient address:

	  boss@yp.to: &god@heaven.af.mil;

       fastforward  sends  each incoming mail message to the recipient address.  The recipient address must include a fully qualified domain name.
       It cannot be longer than 800 bytes.

       If a recipient address is itself a target in the forwarding table, fastforward will recursively handle the instructions	for  that  target.
       Note that @host.dom and user@ wildcards do not apply here; they apply only to the incoming address.

       If a command begins with a letter or number, setforward takes the entire command as a recipient address:

	  boss@yp.to: god@heaven.af.mil;

OWNER ADDRESSES

       If a command begins with a question mark, setforward takes the remaining bytes in the command as an owner address:

	  sos@heaven.af.mil: ?owner-sos@heaven.af.mil;

       fastforward  uses that address as the envelope sender for forwarded mail, so bounces will go back to that address.  (Normally, if a message
       is forwarded to a bad address, it will bounce back to the original envelope sender.)

EXTERNAL MAILING LISTS

       If a command begins with a dot or slash, setforward takes the entire command as the name of a binary mailing list file created by  setmail-
       list:

	  sos@heaven.af.mil: /etc/lists/sos.bin;

       fastforward will read and obey the commands in that file.  The file must be world-readable and accessible to fastforward.

PROGRAMS

       If a command begins with a vertical bar or exclamation point, setforward takes the rest of the command as the name of a program to run:

	  dew@: |dew-monitor;

       For a vertical bar, fastforward feeds the message to that program.  An exclamation point works the same way except that fastforward inserts
       $UFLINE, $RPLINE, and $DTLINE in front of the message.

DUPLICATES

       When fastforward is building the recipient list for a message, it keeps track of the recipient addresses and external mailing lists it  has
       used.  If the same command shows up again, it skips it.	For example:

	  everybody@yp.to: programmers@yp.to, testers@yp.to;
	  programmers@yp.to: joe@yp.to, bob@yp.to;
	  testers@yp.to: joe@yp.to, fred@yp.to;

       A  message to everybody@yp.to will be sent to joe@yp.to only once.  (This also means that addresses in an internal forwarding loop are dis-
       carded.)

       Exception: If a target has an owner address, commands for that target are considered different from commands for ``outside'' targets.

SEE ALSO

       newaliases(1), preline(1), printforward(1), setmaillist(1)

																     setforward(1)