Valid values are
0 - Perform mail lookups when running mail-triggered agents
1 - Do not perform mail lookups when running mail-triggered agents
Another example involves clustered mail servers which implement the Notes.ini parameter, AMGR_DISABLEMAILLOOKUP=1. Normally, new mail triggered agents will run only on the agent signer's mail server. This Notes.ini parameter is intended to allow new mail triggered agents to run on servers other than the agent signer's mail server. In clustered server environments, this parameter can be used to effectively process new mail during a server failover event using agents. However, because new mail triggered agents are also triggered to run at agent cache refresh, these agents may actually run against documents which were previously processed.
In a clustered server situation which implements AMGR_DISABLEMAILLOOKUP=1, new mail will be delivered to only one server (it is then replicated to the clustered servers). Because of this, a new mail event is raised on only the server where the mail was delivered. The new mail triggered agents on this server will process the newly delivered documents. No documents will be processed on the clustered servers. When the agent cache is refreshed at midnight (by default), the agents will then run on every server because the Notes.ini parameter is implemented. On the primary mail server, none of the documents in the database should be new or modified so no documents will be processed. On the clustered servers, all of the documents replicated into the database are new documents since the last time the agent ran (midnight the previous day). These documents will now be processed by the new mail triggered agents.
Can be set via Server/Configuration
Without this setting, mail-triggered agents perform mail lookups.
Also refer to Julies excellent FAQ article for answers to a host of Agent related questions: