Hello, If you use SASL and Posfix and you install system like Prefect Setup said you can't use SASL for e.g. Apache. Apache and authn_sasl module looks for saslauthd socket in /var/run/saslauthd but there is no "mux" and you got "generic failure: checkpass failed" error. So you should make sym link to saslauthd socket. "rm -rf /var/run/saslauthd" "ln -s /var/spool/postfix/var/run/saslauthd /var/run/saslauthd" And now everything works ! Best regards, MvincM