libmail-spf-query-perl 1:1.999.1-3 (amd64 binary) in ubuntu hardy

 The Sender Policy Framework (SPF) protocol relies on sender domains to publish
 a DNS whitelist of their designated outbound mailers. This module, given an
 envelope sender, determines whether a given client IP address is a legitimate
 mail source.
 .
 This package also includes spfquery, a command line interface to the module,
 and spfd, a query proxy for some mail server configurations.
 .
 For more information on SPF, see <http://www.openspf.org>.