SMTP SMTP AUTH LOGIN SASL-IR RFC4954 # # Server-side AUTH LOGIN REPLY AUTH 334 UGFzc3dvcmQ6 REPLY MTIzNA== 235 Authenticated # # Client-side smtp SMTP login authentication with initial response mail body smtp://%HOSTIP:%SMTPPORT/user --mail-rcpt 908@example.com --mail-from 908@example.com -u test:1234 --sasl-ir -T - # # Verify data after the test has been "shot" EHLO user AUTH LOGIN dGVzdA== MTIzNA== MAIL FROM:<908@example.com> RCPT TO:<908@example.com> DATA QUIT mail body .