Input mail filters and the X configuration command are described in Section 7.6.2. In the configuration file, each filter defined with an X configuration command must also be listed with this InputMailFilters option for it to be used. With the mc configuration, the INPUT_MAIL_FILTER macro defines a filter with the X configuration command and automatically lists the filter with this InputMailFilters option. But the MAIL_FILTER mc macro only defines the filter with the X configuration command, and does not list it with this InputMailFilters option. When using the MAIL_FILTER mc macro, you need to also list your filters with this option for them to be used.

The InputMailFilters option is declared like this:

O InputMailFilters=list                  configuration file (V8.12 and later) 
-OInputMailFilters=list                  command line (V8.12 and later) 
define(`confINPUT_MAIL_FILTERS',`list')  mc configuration (V8.12 and later) 

Here, list is of type string. It is a comma-separated list of the names defined by the INPUT_MAIL_FILTER( ) or MAIL_FILTER( ) mc configuration commands (see Section 7.6.3 for a complete description of this option, including possible error messages).

The InputMailFilters option is not safe. If it is specified from the command line, it can cause sendmail to give up any special privileges.