=head2 whitelist Checks to make sure that the incoming message is from a poster in a file of valid posters. The most common use of this module is in conjunction with human moderation; all messages from pre-approved posters are sent straight through via the robomoderator and the rest are relayed to a human moderator for hand checking. This module takes one configuration directive: =over 4 =item whitelist FILE C<FILE> is a list of poster addresses, one per line. Only the address should be included in this file, not the name or other comments. Files ending in C<.db> are reserved for future implementations (eventually, these will automatically be recognized as Berkeley db files for handling large lists of posters). =back There is one possible failure message: =over 4 =item Unknown poster %s The message is from a poster address which isn't in the whitelist of known addresses. =back In addition, during parsing of the configuration directives, one fatal error, which would be passed to error(), is possible: =over 4 =item Can't open whitelist file %s: %s An error occurred while trying to open a file given as a C<FILE> argument to a configuration directive. =back This module takes no arguments.