++--------------------+
+| USING UUCP MAILERS |
++--------------------+
+
+It's hard to get UUCP mailers right because of the extremely ad hoc
+nature of UUCP addressing. These config files are really designed
+for domain-based addressing, even for UUCP sites.
+
+There are four UUCP mailers available. The choice of which one to
+use is partly a matter of local preferences and what is running at
+the other end of your UUCP connection. Unlike good protocols that
+define what will go over the wire, UUCP uses the policy that you
+should do what is right for the other end; if they change, you have
+to change. This makes it hard to do the right thing, and discourages
+people from updating their software. In general, if you can avoid
+UUCP, please do.
+
+The major choice is whether to go for a domainized scheme or a
+non-domainized scheme. This depends entirely on what the other
+end will recognize. If at all possible, you should encourage the
+other end to go to a domain-based system -- non-domainized addresses
+don't work entirely properly.
+
+The four mailers are:
+
+ uucp-old (obsolete name: "uucp")
+ This is the oldest, the worst (but the closest to UUCP) way of
+ sending messages accros UUCP connections. It does bangify
+ everything and prepends $U (your UUCP name) to the sender's
+ address (which can already be a bang path itself). It can
+ only send to one address at a time, so it spends a lot of
+ time copying duplicates of messages. Avoid this if at all
+ possible.
+
+ uucp-new (obsolete name: "suucp")
+ The same as above, except that it assumes that in one rmail
+ command you can specify several recipients. It still has a
+ lot of other problems.
+
+ uucp-dom
+ This UUCP mailer keeps everything as domain addresses.
+ Basically, it uses the SMTP mailer rewriting rules.
+
+ Unfortunately, a lot of UUCP mailer transport agents require
+ bangified addresses in the envelope, although you can use
+ domain-based addresses in the message header. (The envelope
+ shows up as the From_ line on UNIX mail.) So....
+
+ uucp-uudom
+ This is a cross between uucp-new (for the envelope addresses)
+ and uucp-dom (for the header addresses). It bangifies the
+ envelope sender (From_ line in messages) without adding the
+ local hostname, unless there is no host name on the address
+ at all (e.g., "wolf") or the host component is a UUCP host name
+ instead of a domain name ("somehost!wolf" instead of
+ "some.dom.ain!wolf").
+
+Examples:
+
+We are on host grasp.insa-lyon.fr (UUCP host name "grasp"). The
+following summarizes the sender rewriting for various mailers.
+
+Mailer sender rewriting in the envelope
+------ ------ -------------------------
+uucp-{old,new} wolf grasp!wolf
+uucp-dom wolf wolf@grasp.insa-lyon.fr
+uucp-uudom wolf grasp.insa-lyon.fr!wolf
+
+uucp-{old,new} wolf@fr.net grasp!fr.net!wolf
+uucp-dom wolf@fr.net wolf@fr.net
+uucp-uudom wolf@fr.net fr.net!wolf
+
+uucp-{old,new} somehost!wolf grasp!somehost!wolf
+uucp-dom somehost!wolf somehost!wolf@grasp.insa-lyon.fr
+uucp-uudom somehost!wolf grasp.insa-lyon.fr!somehost!wolf
+
+If you are using one of the domainized UUCP mailers, you really want
+to convert all UUCP addresses to domain format -- otherwise, it will
+do it for you (and probably not the way you expected). For example,
+if you have the address foo!bar!baz (and you are not sending to foo),
+the heuristics will add the @uucp.relay.name or @local.host.name to
+this address. However, if you map foo to foo.host.name first, it
+will not add the local hostname. You can do this using the uucpdomain
+feature.
+
+