HELO here.com MAIL FROM:[email protected] RCPT TO:[email protected] STARTTLS AUTH PLAIN dGVzdAB0ZXN0ADEyMzQ= DATA greetings! .
Where AUTH PLAIN is the base64 of the
openssl s_client -starttls smtp -crlf -connect mail.example.com:587 openssl s_client -debug -starttls smtp -crlf -connect mail.example.com:587