relaytest - test if a host is an open relay

in tcpclient relaytest

relaytest is designed for the purpose of checking if a remote SMTP host is an open relay relaytest needs to be invoked by tcpclient

tcpclient -T2 -RH -l0 127.0.0.1 25 /usr/sbin/relaytest

Exits 0 when all the commands are shut down. If a fatal error is encountered, it exits.

tcpclient(1), tcpserver(1),