Symantec Messaging Gateway provides caching functionality that stores directory data from previous requests. This lets the directory data service process requests faster by using this cached data instead of the more time-consuming LDAP directory query.
The cache is enabled by default and entries are added to the cache as they are received and validated. When the directory data service receives a request, it searches all caches until the recipient is found or there are no more caches to search. If the recipient is not found in a cache, the directory data service then searches the data source directories. If the recipient is found in a data source, it adds the recipient to the associated cache.
If the recipient is not found in a data source then the directory data service adds a cache entry to the invalid recipient cache for that data source.
Configure an appropriate cache size based on your system's needs and memory availability. Symantec recommends that you set this value equal to or greater than the number of users and groups in your environment. This list should include distribution lists, contacts, and public folders.
You can control aspects of each of your caches as follows:
Set the cache size and entry life span using the Advanced Settings page.