Comment 7 for bug 1497564

check_smtp_send is not part of monitoring-plugins or nagios-plugins upstream project. It is part of check_email_delivery ( http://buhacoff.net/software/check_email_delivery/) which is packaged into the nagios-plugins-contrib package (at least in Debian). A version 0.7.2 was never in this package and as far as I know, was newer released by upstream