Managing mail with MMDF

Alias and mailing list tables

System-wide alias and mailing list database tables are created by default in the /usr/mmdf/table directory (or the directory specified by the MTBLDIR parameter in the mmdftailor file.)

SCO OpenServer systems include one channel table called alias.n in /usr/mmdf/table.

Three common types of alias definitions include:

system administrative aliases for the local host, for delivery of mail to accounts such as root, mmdf, postmaster, and uucp. Each host should minimally have an alias defined for postmaster.
aliases for mailing lists. With list aliases, error messages and mail about problems with the list are sent to the list owner, not the sender. See ``Maintaining mailing lists''.
aliases mapping users to their ``home'' host machines (the machines on which they receive their mail). This is used especially if you hide host names at your site. See ``Associating users with a home machine''.

How alias tables are created

When you use the Alias Administration Manager to add an alias, you specify whether you want it to be a public address and whether you want to allow bypass. In addition, you can use an alias to redirect or pipe mail to another file or program. Your specifications when defining the alias determine which alias table will contain the alias entry.

These alias tables may be created:

Alias table Alias description

alias allow bypass, not public, not redirected

alias.n no bypass, not public, not redirected

alias.p allow bypass, public, not redirected

alias.t no bypass, not public, redirected or piped

alias.np no bypass, public, not redirected

alias.nt no bypass, not public, redirected or piped

alias.pt allow bypass, public, redirected or piped

alias.npt no bypass, public, redirected or piped

Alias table	Alias description
alias	allow bypass, not public, not redirected
alias.n	no bypass, not public, not redirected
alias.p	allow bypass, public, not redirected
alias.t	no bypass, not public, redirected or piped
alias.np	no bypass, public, not redirected
alias.nt	no bypass, not public, redirected or piped
alias.pt	allow bypass, public, redirected or piped
alias.npt	no bypass, public, redirected or piped

How MMDF uses alias tables

When mail is addressed to postmaster, MMDF routes the mail by first searching the alias tables to expand the postmaster alias to the associated user name. For example, the postmaster entry in the alias table:

   postmaster:	david

Each time MMDF expands an alias successfully, it goes back to the first alias table and begins another search. In a later search, it might find another alias associating david (from the example above) with a local machine name.

MMDF then uses this information when searching the various domain (.dom) tables, which map the local machine name to a fully qualified host name, and the channel (.chn) tables, which map the fully qualified host name to information on how to route the message. ``How MMDF routes mail'' further explains the process for searching configuration files.