sendmail Configuration Table

In response to two entries in the sendmail.cf file, the sendmail program can define macros and classes by looking up values in the sendmailvars configuration table. There are two such commands:

1. Lines that begin with the L key letter are macro definitions, where the values assigned to the specified variable are obtained from the configuration table.

2. Lines that begin with the G key letter are class definitions, where the values assigned to the specified variable are obtained from the configuration table.

The L command has the following syntax:

LXsearch_key

For example: Lmmaildomain

In this case, the search key maildomain looks up a value in the configuration table to assign to the variable m. Most often the single-letter variable name is uppercase, but for internal variables (like m for the mail domain name) it is lowercase.

The G command has the following syntax:

GCsearch_key

For example: GVuucp-list

In this case, the search key uucp-list looks up a value in the configuration table to assign to the variable V.

In both cases, matching of the search key is case sensitive.

Both commands have counterparts for defining macros or classes within the sendmail.cf file, rather than the lookup table. D is the counterpart of L; C is the counterpart of G.

If you use NIS+ to administer the network, you can maintain a global version of the sendmailvars information. In addition to the NIS+ table or as an alternative, you can maintain the data in /etc/mail/sendmailvars. The order in which these sources are searched by sendmail is controlled by the sendmailvars entry in the /etc/nsswitch.conf file. By default, the search order is files nisplus, which means sendmail attempts to look up information in the local file before going to the NIS+ table.

Entries in an /etc/mail/sendmailvars file have the following format:

search_key [value1 value2 value3...]

You might follow the search key by a tab or several spaces; seperate values are with a single space.

The NIS+ sendmailvars table has two columns: a key column and a value column. The value column can have one or more values, each separated by a space. For example:

Most mail variables should be defined in the NIS+ table. However, in special cases, systems can override the global setting for a variable by including it in their local /etc/mail/sendmailvars file.