SMTP IDN # Server-side # Client-side smtp IDN !win32 codeset-utf8 LC_ALL=C.UTF-8 SMTP without SMTPUTF8 support - UTF-8 based sender (host part only) From: different To: another body smtp://%HOSTIP:%SMTPPORT/%TESTNUMBER --mail-rcpt recipient@example.com --mail-from sender@%hex[%c3%a5%c3%a4%c3%b6]hex%.se -T - # Verify data after the test has been "shot" EHLO %TESTNUMBER MAIL FROM:%LTsender@xn--4cab6c.se%GT RCPT TO:%LTrecipient@example.com%GT DATA QUIT From: different To: another body .