RelayCountry - add message metadata indicating the country code of each relay
loadplugin Mail::SpamAssassin::Plugin::RelayCountry
By the RelayCountry plugin attempts to determine the domain country
codes of each relay used in the delivery path of messages and add that
information to the message metadata as "X-Relay-Countries", or
the _RELAYCOUNTRY_
header markup.
This plugin requires the IP::Country module from CPAN.