We use cookies on our website to ensure we provide you with the best experience on our website. By using our website, you agree to the use of cookies for analytics and personalized content.This website uses cookies. More Information
It seems like your browser didn't download the required fonts. Please revise your security settings and try again.

Why are messages being Deferred for reason 'Possible Outbreak' within the ESS or the Cloud Protection Layer?

  • Type: Knowledgebase
  • Date changed: 7 months ago
Solution #00006386

- The Barracuda Email Security Service
- The Barracuda Cloud Protection Layer

Barracuda Email Security Service (ESS) is a single service with thousands of domains. The 'Possible Outbreak' feature is not a per domain rule; it actually covers the entire service. If an email-sending entity sends out a message to thousands of people across our service, it may be picked up as a Possible Outbreak event. These are often false positives which will later go away. The sending server should get back a 4xx message for 'Possible Outbreak' and will retry sending the message at a later time. The ESS watches for this, and if the message is retried, it assumes it is legitimate and the Possible Outbreak delay is removed.

Link to this Page: