cf/README for sendmail 8.12.3

Eric Allman of the Sendmail Consortium

Non-SMTP Based Configurations

These configuration files are designed primarily for use by SMTP-based sites. They may not be well tuned for UUCP-only or UUCP-primarily nodes (the latter is defined as a small local net connected to the rest of the world via UUCP). However, there is one hook to handle some special cases.

You can define a ``smart host'' that understands a richer address syntax using:

define(`SMART_HOST', `mailer:hostname')

In this case, the ``mailer:'' defaults to "relay". Any messages that can't be handled using the usual UUCP rules are passed to this host.

If you are on a local SMTP-based net that connects to the outside world via UUCP, you can use LOCAL_NET_CONFIG to add appropriate rules. For example:

define(`SMART_HOST', `uucp-new:uunet')
R$* < @ $* .$m. > $*	$#smtp $@ $2.$m. $: $1 < @ $2.$m. > $3

This will cause all names that end in your domain name ($m) to be sent via SMTP; anything else will be sent via uucp-new (smart UUCP) to uunet. If you have FEATURE(`nocanonify'), you may need to omit the dots after the $m. If you are running a local DNS inside your domain which is not otherwise connected to the outside world, you probably want to use:

define(`SMART_HOST', `')
R$* < @ $* . > $*	$#smtp $@ $2. $: $1 < @ $2. > $3

That is, send directly only to things you found in your DNS lookup; anything else goes through SMART_HOST.

You may need to turn off the anti-spam rules in order to accept UUCP mail with FEATURE(`promiscuous_relay') and FEATURE(`accept_unresolvable_domains').