SMTP
VRFY
IDN
#
# Server-side
#
# Client-side
smtp
idn
LC_ALL=en_US.UTF-8
LC_CTYPE=en_US.UTF-8
perl -MI18N::Langinfo=langinfo,CODESET -e 'die "Needs a UTF-8 locale" if (lc(langinfo(CODESET())) ne "utf-8");'
SMTP external VRFY without SMTPUTF8 support (IDN Enabled) - UTF-8 based recipient (host part only)
smtp://%HOSTIP:%SMTPPORT/964 --mail-rcpt user@åäö.se
#
# Verify data after the test has been "shot"
EHLO 964
VRFY user@xn--4cab6c.se
QUIT