Alert or Keep Alive Messages

I have Kiwi Syslog Server version 9.8.  I would like to setup a notification where the application sends an email if it doesn't receive syslogs from a sender(s).  I noticed there is a built in alert where you can be notified if overall a certain amount of syslogs are not received within an hour.  However, I'd like something with a smaller window of 5 minutes.  Also, I noticed keep alive messages can be injected in the received syslogs at a certain interval, but I can't see how I'd make a rule to detect if that keep alive syslog message goes missing.  Is it possible the built-in alert can have a shorter window than 1 hour OR how would I configure a rule that sends notification if the keep-alive message goes missing?  Thanks.