Manuel Monteiro wrote:

Dear all,

I have a mail server based on a CentOS 5.3 machine with postfix.

Most of our users are on LDAP (on localhost) but we also have some local users and we are using PAM for authentication.

Are you running nscd on the server? That should smooth out LDAP blips, though I would disable nscd's dns caching in /etc/nscd.conf

Is postfix configured to talk directly to LDAP ? What does the configuration look like?

nate