be in the MIME format. Design variations and considerations For real-time journaling, the journal message is sent for further processing at the same time the actual electronic message is being sent. For periodic journaling, the journal message is stored in a secure, local storage area before being archived at the enterprise level on a periodic basis, typically after business hours. The processing of journal messages after their creation also varies. A journal message may be forwarded in real-time directly to an archival and storage system, where any storage system processing may then take over. Alternatively, a journal message may be forwarded in real-time to a journaling mailbox, and then retrieved from the journaling mailbox with periodic extractions to the archival system, where any archival system processing would then take over. Rule-based selective journaling is also well known and in use. With rule-based selective journaling, electronic messages are journaled only if they pass a specific set of rules created by an administrator, possibly relating to specific senders/recipients, keywords, or subjects of the message. When a journaling message uses the same transport format as normal communications, the same infrastructure can be used to transport the journaling message to a preferred destination. In such cases, journaling messages should contain an identifier indicating they are a journaling message and not a normal communication. This will prevent journaling loops from occurring when multiple mail servers are in use, as a second mail server might receive the journaling message before it reaches the journaling storage destination. Differences between journaling and archiving Journaling refers to capturing information about an electronic message while it is in transit. Which messages and the kind of information that is captured should be defined by a system administrator or compliance agent. The journaled message should be encrypted and users should not have access to their own journaled message store. Archiving, on the other hand, is primarily dedicated for backing up communications or removing them from their original location to an off-site location. Archiving generally does not occur while the electronic message is in transit and users may have access to their own archived messages. The journaling system may, however, be used as a communication interface to the archival system. Implementations Microsoft Exchange Microsoft released a journaling feature in service packs for Exchange 2000 and 2003, during 2004. Microsoft's journaling feature uses real-time journaling to a journaling mailbox. The journaling feature uses a