auxpropfunc error no mechanism available errors 

Overview

Once you configured Postfix + MySQL + Courier imap + SASL SMTP Auth,

And you configured SASL with using courier auth daemon as the following config.
/usr/lib/sasl2/smtpd.conf

pwcheck_method: authdaemond
log_level: 3
mech_list: plain login
authdaemond_path:/var/spool/authdaemon/socket

You may notice there have a error message when every smtp attempt.

Mar 12 06:10:32 lxpsrv01 postfix/smtpd[29770]: sql_select option missing
Mar 12 06:10:32 lxpsrv01 postfix/smtpd[29770]: auxpropfunc error no mechanism available
Mar 12 06:10:32 lxpsrv01 postfix/smtpd[29770]: auxpropfunc error invalid parameter supplied

Solution

Remove SASL sql package, because you don’t need it while you configured to use authdaemon instead of direct sql query. Or simply ignore it, it’s no harm and just annoying.

rpm -e cyrus-sasl-sql