In general, we recommend that you start off holding the messages Spam Protection identifies, and start bouncing messages once some statistics have been gathered for your account.
Holding your messages:
Bouncing your messages:
Additionally, many users find it convenient to set accurate conditions to bounce, so they can focus their attention on checking the results of less accurate conditions for false positives.
Remember, if you choose to bounce your mail, you can still whitelist addresses that are incorrectly caught by Spam Protection. However, if you choose to bounce your spam, we cannot retrieve a real message under any circumstances. Your correspondent will need to send the message again.