*****************************************************
    * This section is really obsolete, and is preserved	*
    * only for back compatibility.  You should plan on	*
    * using mailertables for new installations.	  In	*
    * particular, it doesn't work for the newer forms	*
    * of UUCP mailers, such as uucp-uudom.		*
    *****************************************************

Complex sites will need more local configuration information, such as lists of UUCP hosts they speak with directly. This can get a bit more tricky. For an example of a "complex" site, see cf/ucbvax.mc.

If your host is known by several different names, you need to augment the $=w class. This is a list of names by which you are known, and anything sent to an address using a host name in this list will be treated as local mail. You can do this in two ways: either create the file /etc/sendmail.cw containing a list of your aliases (one per line), and use ``FEATURE(use_cw_file)'' in the .mc file, or add the line:

	Cw alias.host.name

at the end of that file. See the ``vangogh.mc'' file for an example. Be sure you use the fully-qualified name of the host, rather than a short name.

The SITECONFIG macro allows you to indirectly reference site-dependent configuration information stored in the siteconfig subdirectory. For example, the line

	SITECONFIG(uucp.ucbvax, ucbvax, U)

reads the file uucp.ucbvax for local connection information. The second parameter is the local name (in this case just "ucbvax" since it is locally connected, and hence a UUCP hostname). The third parameter is the name of both a macro to store the local name (in this case, $U) and the name of the class (e.g., $=U) in which to store the host information read from the file. Another SITECONFIG line reads

	SITECONFIG(uucp.ucbarpa, ucbarpa.Berkeley.EDU, W)

This says that the file uucp.ucbarpa contains the list of UUCP sites connected to ucbarpa.Berkeley.EDU. The $=W class will be used to store this list, and $W is defined to be ucbarpa.Berkeley.EDU, that is, the name of the relay to which the hosts listed in uucp.ucbarpa are connected. [The machine ucbarpa is gone now, but I've left this out-of-date configuration file around to demonstrate how you might do this.]

Note that the case of SITECONFIG with a third parameter of ``U'' is special; the second parameter is assumed to be the UUCP name of the local site, rather than the name of a remote site, and the UUCP name is entered into $=w (the list of local hostnames) as $U.UUCP.

The siteconfig file (e.g., siteconfig/uucp.ucbvax.m4) contains nothing more than a sequence of SITE macros describing connectivity. For example:

	SITE(cnmat)
	SITE(sgi olympus)

The second example demonstrates that you can use two names on the same line; these are usually aliases for the same host (or are at least in the same company).