Some databases, such as user
, are a part of UNIX.
Others are a part of sendmail, like the User Database described
above. Many, however, are implemented in rules and rule sets.
This latter sort of database is therefore available via the m4
technique. Currently, all m4 available databases are implemented
as FEATUREs.
Table 33.7
lists those available. The second column shows you where to find
information about each.
Feature | Version | Description | |
---|---|---|---|
domaintable | Section 19.6.10, FEATURE(domaintable) | V8.1 and above | Accept other domains as equivalent to the local domain |
genericstable | Section 19.6.11, FEATURE(genericstable) | V8.8 and above | Transform sender addresses |
mailertable | Section 19.6.14, FEATURE(mailertable) | V8.1 and above | Select new delivery agents based on an external database |
virtusertable | Section 19.6.28, FEATURE(virtusertable) | V8.8 and above | Support for virtual domains |
Note that these FEATUREs do not necessarily need to be used with
database files. To illustrate, consider the domaintable
feature
(see Section 19.6.10). It is included in your mc
file like this:
FEATURE(`domaintable',`nis domaintable')
Here, we specify that the database is to be an nis map. This
causes the key
to be looked up via the nis services and
any match to be returned the same way.