As a message passes through the last of all of the defense layers, it is scored for spam probability. This score ranges from 0 (definitely not spam) to 10 or higher (definitely spam). Based on this score, the Barracuda Email Security Gateway either tags (inbound messages only), quarantines, blocks or allows (or sends, for outbound) the message.
Once you have more experience with the Barracuda Email Security Gateway, you can adjust how aggressively the system deals with spam. For example, you may decide to tag (inbound only) or quarantine spam instead of blocking it. Details of spam scoring limits for your Barracuda Email Security Gateway are discussed in the Help file on the BASIC > Spam Checking page.