% perl -MMIME::Base64 -e 'print encode_base64("\000jms1\@jms1.net\000not.my.real.password")' AGptczFAam1zMS5uZXQAbm90Lm15LnJlYWwucGFzc3dvcmQ= % telnet 1.2.3.4 25 % telnet 1.2.3.4 25 220 a.mx.jms1.net NO UCE ESMTP ehlo testing 250-a.mx.jms1.net NO UCE 250-STARTTLS 250-PIPELINING 250 8BITMIME quit 220 a.mx.jms1.net NO UCE ESMTP ehlo testing 250-a.mx.jms1.net NO UCE 250-AUTH LOGIN PLAIN 250-AUTH=LOGIN PLAIN 250-PIPELINING 250 8BITMIME Assuming the server supports AUTH, we will send the actual AUTH command to try and authenticate. AUTH PLAIN AGptczFAam1zMS5uZXQAbm90Lm15LnJlYWwucGFzc3dvcmQ= mail from: <nospam@jms1.net> 250 ok rcpt to: <nospam@jms1.net> 250 ok data 354 go ahead From: John <nospam@jms1.net> To: Nobody <nospam@jms1.net> Subject: fnord hail eris! . 250 ok 1113954693 qp 29052 quit 221 a.mx.jms1.net NO UCE