When journaling on your email server is not available or is not a practical option, you can use a combination of the Barracuda Message Archiver and the Barracuda Email Security Gateway to capture both external and internal emails via SMTP. To capture messages sent from external Internet users, you can leverage the journaling capabilities of the Barracuda Email Security Gateway to copy messages to your Barracuda Message Archiver. To capture messages sent from inside your organization, you can configure internal email clients to use the Barracuda Message Archiver as an SMTP relay placed in front of your internal email server.
The following image illustrates SMTP relay deployment:
