The RAPNAP (Return Address, Peer Network Address Pair) database is a public resource provided by TipJar LLC.
The RAPNAP database is a listing of senders of e-mail and the e-mail postmarks normally associated with those senders.
You may check a RAPNAP entry by requesting a web page from the pay2send RAPNAP web service.
The pay2send RAPNAP web service is a CGI program which lives at http://pay2send.com/cgi/rapnap/check.
The check program accepts several CGI variables:
Challenge messages are sent when both the target and subject line are listed, and the RAPNAP being queried has not had a challenge sent in the last week.
the reserved key of
ipv4 can be used for a demonstration. There
is a limit on the number of queries that can be made from any given version 4 IP address
each day, using the reserved key.
A perl module, RAPNAP::client, is available on CPAN to facilitate use of the RAPNAP database.
Working MDA software that checks the database before appending to a MBOX file is available by request.