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smtptest - interactive SMTP test program
smtptest
[ -t keyfile ] [ -p port ] [
-m mechanism ]
[ -a userid ] [ -u userid ] [
-k num ] [ -l num ]
[ -r realm ] [ -f file ] [
-n num ] [ -s ] [ -c ]
[ -i ] [ -o option=value
] [ -v ] hostname
smtptest is a utility that allows you to authenticate to a SMTP server and interactively issue commands to it. Once authenticated you may issue any SMTP command by simply typing it in. It is capable of multiple SASL authentication mechanisms and handles encryption layers transparently. This utility is often used for testing the operation of a smtp server. Also those developing SMTP clients find it useful.
-t keyfile
Enable TLS. keyfile contains the TLS public and private keys.