Finally I have Cyrus authenticating through the LDAP server. I followed instructions here: http://www.magic-lamp.org/howto_postfix-cyrus.0.html The only difference is that in FC4 you obviously use yum to install packages. In particular make sure you have installed cyrus-imapd-utils so that you have the cyradm tool. Also, where he mentions /etc/conf.d/saslauthd.conf, change that to /etc/sysconfic/saslauthd. -- Kind regards, John Francis