Which of the following is NOT a method to populate the Mimecast Archive?

Populating the Mimecast Archive involves various methods, each serving a specific purpose in managing email data.

Ingested messages refer to emails that are integrated into the archive from various sources, and this is a common practice for ensuring that all relevant communications are stored for retention and compliance purposes. Outbound mailflow, on the other hand, consists of emails that are sent out of an organization and can be captured and archived by Mimecast as part of its comprehensive email management functions. Journal mailflow is also a recognized method used in many organizations to create a complete record of all email communications, as it captures messages for archiving by journaling all email traffic.

Archived user mail specifically refers to emails that have already been archived and aren't actively being sent or received. It's more of a storage status rather than a process or method for populating new items into the Mimecast Archive. Therefore, while archived user mail may exist within the archive as a part of the historical data, it does not contribute to populating the archive in the same way that the other options do.