Great link to information regarding testing SMTP AUTH:

• http://qmail.jms1.net/test-auth.shtml

To test SMTP AUTH I did the following:

[server]# perl -MMIME::Base64 -e ‘print encode_base64(“\000test\@domain.com\000testpassword”)’
AHRlc3RAZG9tYWluLmNvbQB0ZXN0cGFzc3dvcmQ=

[server]# perl -MMIME::Base64 -e ‘print decode_base64(“AHRlc3RAZG9tYWluLmNvbQB0ZXN0cGFzc3dvcmQ=”)’
[email protected]

Then connect to the server and try putting in the above SMTP AUTH details:

[server]# telnet localhost 25
Trying 127.0.0.1…
Connected to localhost (127.0.0.1).
Escape character is ‘^]’.
220 localhost ESMTP
ehlo testing
250-localhost
250-STARTTLS
250-PIPELINING
250 8BITMIME
AUTH PLAIN AHRlc3RAZG9tYWluLmNvbQB0ZXN0cGFzc3dvcmQ=
235 go ahead
quit
221 localhost

URLs:

• Quick CLI SMTP AUTH script to test authentication