I have RH ES 3.0 running postfix-2.0.11-4 with smtp authentication and saslauthd service, all ok. I have in main.cf: broken_sasl_auth_clients = yes smtpd_sasl_auth_enable = yes smtpd_sasl_security_options = noanonymous smtpd_client_restrictions = check_client_access smtpd_sender_restrictions = reject_unknown_sender_domain, hash:/etc/postfix/access smtpd_recipient_restrictions = permit_mynetworks, permit_sasl_authenticated, reject_unauth_destination the file /usr/lib/sasl2/smtpd.conf with: pwcheck_method: saslauthd mech_list: plain login /etc/sysconfig/saslauthd with: MECH=pam and /etc/pam.d/smtp with auth required pam_stack.so service=system-auth account required pam_stack.so service=system-auth Problem: When I upgrade to postfix-2.0.16-13.RHEL3 the smtp authenticacion failed, my clients are Outlook Express 6.0. I must to regret to postfix-2.0.11-4 version. I don't use sendmail, I only use Postfix. But when I install the last version of sendmail that resolv a similiar problem then Postfix 2.0.16-13 works ok. But I think that don't be necessary install sendmail to postfix works.
postfix is using SASLv1, now. There was a problem with SASLv2 and LDAP. Please have a look at: https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=125383#c1 This is also relevant for postfix.