Filters are processed sequentially, one-by-one, by the EventSentry agent. If an event matches multiple filters, then every filter matching the event will send the event information to the configured target. This usually happens when more than one filter is configured to use "All Targets".
To avoid seeing events multiple times:
Note: Starting with EventSentry v2.7x, notifications will never receive the same event more than one time, even if multiple filter rules match the same event.