If you are deploying the Barracuda Cloud Archiving Service with the Barracuda Email Security Service, relaying archived mail through the Barracuda Email Security Service can result in mail being blocked for a variety of reasons including rate limits, spam, scoring, or content. To avoid this, you must archive mail directly to your archiving appliance or service and not through the Barracuda Email Security Service. This can be accomplished by configuring a secondary connector on most hosted services and Microsoft Exchange. For details, see Journaling Deployment Options.
If you need additional direction, contact Barracuda Networks Technical Support.