If you are having issues getting postfix email server to authenticate with saslauthd, your solution might be found in a missing symlink. Remember that postifx runs in a chroot environment.
I found the following warning message in /var/log/mail.log: warning: SASL authentication failure: cannot connect to saslauthd server: No such file or directory
Fixing postfix and saslauthd: cannot connect to saslauthd | nfolamp blog.