I am using LDAP as backend for Postfix for all email accounts. Any email coming to the server is checked against LDAP to check if email is valid, and deliver it accordingly.
It works almost perfectly but I have a big problem that arise when receiving (or sending) too many emails at the same time.
It looks like slapd server is overwhelmed with too many requests at the same time, which makes postfix getting timeouts.
On the postfix side hopefully it's only a "temporary lookup failure" but I want to correct that problem.
In the logs I get two kind of LDAP errors :