I installed Postfix & Dovecot on Debian.
Then I tried using SMTP authentication according to this guide:
http://www.postfix.org/SASL_README.html
Unfortunately the following test tails:
telnet localhost 25
auth plain <base64 encoded usernaem/password>
We get a "535 5.78 Error: authentication failed:"
in var/log/mail.warn we habe a new line which is: "warning: localhost[127.0.0.1]: SASL PLAIN authentication failed:"
unfortunately it does not say what is wrong. Any ideas?
It's really stupid. But here is the reason what went wrong:
we generated the base 64 string according to the documentation:
unfortunately our password started with a number. After changing the password to start with a character it worked fine!