Called by the mailet container to indicate to a matcher that the matcher is being taken out of service. This method is only called once all threads within the matcher's service method have exited or after a timeout period has passed. After the mailet container calls this method, it will not call the match method again on this matcher.
This method gives the matcher an opportunity to clean up any resources that are being held (for example, memory, file handles, threads) and make sure that any persistent state is synchronized with the matcher's current state in memory.