SMTP
VRFY
--request
#
# Server-side
250
#
# Client-side
smtp
SMTP VRFY with custom request
# the custom request just does it lowercase to remain the same command
smtp://%HOSTIP:%SMTPPORT/%TESTNUMBER --mail-rcpt recipient --request "vrfy"
#
# Verify data after the test has been "shot"
EHLO %TESTNUMBER
vrfy recipient
QUIT