rDNS files

Some of the options described below search files for rDNS names. In all those cases, the format of the files is the same. Blank lines and lines beginning with # are ignored. Every other line in the file is expected to contain a single entry.

Individual names may be given as separate entries. Those names will be matched literally. For example:

mail.example.com

smtp.example.com

Two names will be matched by these entries, mail.example.com and smtp.example.com.

The rDNS names may also use wildcards by beginning with dots (.). For example, if the file contained the following entry:

.example.com

The names example.com, mail.example.com and mail.internal.example.com will match. If the file contained the following entry:

.mail.example.com

The names mail.example.com and internal.mail.example.com will match but example.com and internal.example.com will NOT.