Writing the Configuration Files

The configuration for the Brewery works as follows: all hosts except the mail server vstout itself route all outgoing mail to the server, using smart host routing. vstout itself sends all outgoing mail to the real smart host that routes all of the Brewery's mail; this host is called moria.

The standard config file for all hosts other than vstout looks like this:

           #
           # Our domain:
           visible domain=vbrew.com
           #
           # What we name ourselves
           visible name=vbrew.com
           #
           # Smart-host routing: via SMTP to vstout
           smart path=vstout
           smart transport=smtp

This is very similar to what we used for a UUCP-only site. The main difference is that the transport used to send mail to the smart host is, of course, SMTP. The visible_domain attribute makes smail use the domain name instead of the local hostname on all outgoing mail.

On the UUCP mail gateway vstout, the config file looks a little different:

           # Our hostnames:
           hostnames=vbrew.com:vstout.vbrew.com:vstout
           #
           # What we name ourselves
           visible name=vbrew.com
           #
           # in the uucp world, we're known as vbrew.com
           uucp name=vbrew.com
           #
           # Smart transport: via uucp to moria
           smart path=moria
           smart transport=uux
           #
           # we're authoritative for our domain
           auth domains=vbrew.com

This config file uses a different scheme to tell smail what the local host is called. Instead of giving it a list of domains and letting it find the hostname with a system call, it specifies a list explicitly. The above list contains both the fully qualified and the unqualified hostname, and the domain name all by itself. This makes smail recognize [email protected] as a local address, and deliver the message to janet.

The auth_domains variable names the domains for which vstout is considered to be authoritative. That is, if smail receives any mail addressed to host.vbrew.com where host does not name an existing local machine, it rejects the message and returns it to the sender. If this entry isn't present, any such message will be sent to the smart-host, who will return it to vstout, and so on until it is discarded for exceeding the maximum hop count.