I am trying to send mail from my java application simply connecting on localhost:25 with empty login and password (I have to state them due to API).
Mail sending is failed then with
2010-03-21 12:20:01 login authenticator failed for localhost [127.0.0.1]: 535 Incorrect authentication data
On the other hand, when I am sending mail with telnet by:
$ telnet localhost 25 ehlo ... mail from:... rcpt to:... data: ...
it works perfectly.