When changes are made to groups in the NAMES.NSF on a Domino server (e.g. people added, modified, or deleted), the Domino server may take up to several minutes before these changes take effect. A command at the server console can help.
show nlcache – displays the current status of the NameLookup cache
show nlcache reset – resets the NameLookup cache
Because executing this command on the Domino server generates a high load, it should only be run during off-peak hours on heavily used servers with a large directory.