NAME

       courieruucp - Sample Courier mail filter

SYNOPSIS

       makeuucpneighbors

DESCRIPTION

       The Courier mail server is capable of sending and receiving mail via UUCP. Courier does not implement
       UUCP directly, but instead uses third-party UUCP software, which you must install separately. Courier's
       UUCP support is provided automatically by the courieruucp module, which is compiled and installed by
       default.

       Courier sends mail via UUCP by issuing a request via uux to execute the rmail command on the remote UUCP
       node. Courier passes the message envelope sender to rmail via the -f flag, and lists the message envelope
       recipients as the remaining arguments. Message envelope addresses and E-mail addresses in the headers of
       the message will be appropriately rewritten.

       Courier will only send mail via UUCP if it knows about the recipient's UUCP node. The configuration file
       /etc/courier/uucpneighbors is a plain text configuration file. The makeuucpneighbors script compiles this
       configuration file into a binary database that is read by Courier. Changes to /etc/courier/uucpneighbors
       do not take effect until makeuucpneighbors is executed, and Courier is restarted.

       /etc/courier/uucpneighbors may also be a subdirectory instead of a plain text file, in which case the
       contents of all text files in this subdirectory is automatically concatenated by the makeuucpneighbors
       script.

   Contents of /etc/courier/uucpme
       This configuration file must be initialized to contain the UUCP node name that this machine is known to
       its neighbors. If /etc/courier/uucpme does not exist, Courier uses the first node name of the hostname
       specified by the /etc/courier/me configuration file.

   Contents of /etc/courier/uucpneighbors
       Note that in addition to creating this configuration file you must also configure your UUCP software to
       appropriately route UUCP mail to the specified nodes, which is a completely separate task. Blank lines in
       this file are ignored. Lines that start with the # character are comments, and are also ignored. The
       remaining lines are in the following format:

           node<TAB>flags

       node is a UUCP node, such as "apple" or "food!fruits!apple". <TAB> is a single tab character, and flags
       is zero or more of single character flags described below. The tab character can be ommited if there are
       no flags.

       If there is an entry for node in /etc/courier/uucpneighbors then Courier will accept mail for any address
       of the form "node!user", but not "node!nodule!user". In order to accept mail for "node!nodule!user" you
       must enter both "node" and "node!nodule", unless you use the F or the G flag.

       The flags are as follows:

       F
           Unrestricted forwarding. This flag will accept any UUCP path that starts with the specified node.
           Example:

               food<TAB>F
           This will accept "food!fruits!apple", "food!fruits!banana", "food!drinks!orangejuice", and so on. You
           may simply list all your immediate UUCP neighbors using the F flag, and accept mail to any address
           that's reachable via any neighbor.

       G
           This is a gateway. This flag is identical to the F flag, except that rmail is executed on the
           specified node. Normally, Courier will issue a uux request to run rmail on the last node, for example
           "uux food!fruits!rmail apple". Using G instead of F will run rmail on the listed node, for example
           "uux food!rmail fruits!apple".

       R
           This is a relay. This flag is used where neither F or G flags are appropriate, but you want to run
           rmail on this node. For example:

               food!fruits
               food<TAB>R
           In this example mail to "food!fruits!apple" is sent by executing "uux food!rmail fruits!apple". If
           the R flag is not specified, then Courier will request "uux food!fruits!rmail apple".

   Contents of /etc/courier/module.uucp
       This is the standard Courier module configuration file.

       MAXDELS
           Maximum simultaneous UUCP deliveries. This setting is a bit misleading. From Courier's viewpoint, a
           delivery consists only of running uux to queue up the message via UUCP. Once uux returns, the message
           is delivered, as far as Courier is concerned. UUCP is responsible for getting the message the rest of
           the way. Therefore, UUCP deliveries tend to be fairly quick, and it is not necessary to configure a
           large number of concurrent courieruucp processes, since each one will terminate quickly. Once uux
           terminates, the UUCP software is responsible for queueing and sending the message.

       MAXHOST
           Maximum simultaneous UUCP deliveries to the same UUCP node. Since UUCP deliveries tend to be fairly
           quick, it is not usually necessary to use MAXHOST to limit concurrent deliveries to the same UUCP
           node, so MAXHOST should generally be set to the same value as MAXDELS.

       MAXRCPT
           Maximum recipients per message. When the same message is sent to multiple recipients on the same UUCP
           node, Courier is capable of asking to run rmail only one, and listing all the recipients together.
           MAXRCPT specifies the upper limit on the number of recipients that are batched together. You want to
           set a limit based on any limitations on the length of command lines that's imposed by the operating
           system. Sending the same message to different UUCP nodes is always handled as separate deliveries.

HEADER AND ADDRESS REWRITING

       Courier is certainly capable of relaying mail between the Internet - via ESMTP - and UUCP-land, rewriting
       headers and addresses appropriately. The address rewriting rules are fixed, but they are expected to work
       in nearly every case. If you find yourself in some oddball situation, you'll just have to invest the time
       to add custom header rewriting code.

       If you are example.com, and your UUCP node is example, then <user@example.com> gets rewritten as
       example!user.

       Internet mail may be sent via ESMTP to your UUCP neighbor apple!john by sending it to
       <apple!john@example.com>. When that's forwarded via UUCP the return address of <someone@domain.com> will
       be rewritten as example!domain.com!someone.

       apple!john will get the mail with this return address, which should be repliable back to the sender.
       Courier's UUCP module will receive the UUCP address domain.com!someone, and translate it back as
       <someone@domain.com>.

BUGS

       Courier does not support defining multiple UUCP node names in /etc/courier/uucpme.

SEE ALSO

       esmtpd(8)[1], couriertcpd(8)[2], courier(8)[3].

AUTHOR

       Sam Varshavchik
           Author

NOTES

        1. esmtpd(8)
           http://www.courier-mta.org/esmtpd.html

        2. couriertcpd(8)
           http://www.courier-mta.org/couriertcpd.html

        3. courier(8)
           http://www.courier-mta.org/courier.html