SMTP
VRFY
#
# Server-side
REPLY VRFY 550 Unknown user
#
# Client-side
smtp
SMTP unknown user VRFY
smtp://%HOSTIP:%SMTPPORT/%TESTNUMBER --mail-rcpt recipient
#
# Verify data after the test has been "shot"
# 8 - CURLE_WEIRD_SERVER_REPLY
8
EHLO %TESTNUMBER
VRFY recipient
QUIT