How do the Smart Host Relay Check Work?

The check for smart host relay works like this:
- the check is performed every 30 seconds on the whole set of relay servers defined
- when one or more servers are unresponsive, a counter starts
- when the number of bad checks reaches 5 (2 minutes after the first bad check), the Not Good flag is raised
- when all the relay servers give a positive reply, the counter is reset.

The reason for the counter is that it may happen that one or more mail servers may appear down (slow internet, server slow to reply etc.), so it is considered a bad server after 5 attempts.
However, as soon as all the relay servers are found online, the Status is restored to Perfect.

The reason for a possible delay is: When the bad server is deleted from the list, the check process is at the beginning of the 30 seconds sleep, so it won't start checking the remaining servers before that time.