The LDAP directory server (slapd) provides directory information for the messaging system. If slapd is down, the system will not work properly. If slapd response time is too slow, this will affect login speed and any other transaction that requires LDAP lookups.
Client POP, IMAP, or Webmail Authentication fails or slower than expected.
MTA not working properly
Check that ns-slapd process is running.
Check slapd log files access and errors in slapd-instance/logs/
Check the ns-slapd response time while searching for a user.
See also 27.8.1 immonitor-access