The AsyncOS doesn't really keep in memory of what it has previously seen with respect to repeat/duplicate notifications.
However, if there is a common notification like Print Server unavailable or those out of office notifications, what you could do is create either a command line Message Filter or a GUI content filter that detects that particular notification and inserts a custom header. Then keeps count of how often it's seen the exact same message come through.
Though this KB below is meant for detecting and stopping message loops, you can try to see if it can be applied to your scenario. But in general, the AsyncOS doesn't really remember the Subject or the type of message that just came through 5 minutes ago.
What is a mail loop?
http://tinyurl.com/yl2ubf