use strictures;
use WWW::Mechanize;

my $mech = WWW::Mechanize->new();
$mech->credentials( api => "key-da0f99505ece11e48064d6516832a126" );

$mech->post( "https://api.mailgun.net/v2/xyz.mailgun.org/messages",
             [ from => 'Mailgun Sandbox <postmaster@sandboxyz.mailgun.org>',
               to => 'Kitty <fluffy@cats.co.uk.jp.org>',
               subject => 'OHAI',
               text => 'Congratulations! You are a winner. A loser no more!!' ]);

print $mech->response->as_string, $/;