I have a Ubuntu Virtual Server handling all my mail, recently after an apt-get upgrade I was unable to send email using my Postfix Virtual User setup through Courier and SASL.
I kept getting the following error in my logs:
Aug 18 07:53:53 marvin postfix/smtpd[23938]: warning: SASL authentication failure: cannot connect to Courier authdaemond: No such file or directory Aug 18 07:53:53 marvin postfix/smtpd[23938]: warning: localhost[127.0.0.1]: SASL LOGIN authentication failed: generic failure
After consulting with Google for at least an hour i finally hit upon a page that helped me.