1.3 Overview

The Spam Confidence Level Protocol enables the client to process e-mail messages that are likely to be phishing messages or spam by doing the following:

  • Blocking the delivery of messages to the Inbox folder that are from specific senders or classes of senders.

  • Allowing the delivery of messages that are either from specific senders or to specific recipients, regardless of whether the messages are identified as spam or phishing messages.

The Junk Email rule, which is an extended rule, specifies the client's spam and phishing preferences. When an e-mail message is delivered to a server, the server applies the Junk Email rule against the properties of the e-mail message to determine whether to put the message in the Junk Email folder.

Clients can use the junk email move stamp to indicate that a message bypasses the client's spam filter. A common scenario in which this occurs is when the client's spam filter has already moved the message to the Junk Email folder once. If the user has retrieved a message from the Junk Email folder, it will not be reprocessed. Clients can also set this property to populate a message store with trusted Message objects that are never spam but might look like spam to a spam filter. The RSS Object Protocol, as described in [MS-OXORSS], is a practical example of this method.