Yes. Two of the approaches are methods to get messages into an archive. Journaling, typically used in Microsoft...
Exchange environments, creates a copy of a message, and that copy can be sent to a second location. In the email archiving case, it's usually sent into a piece of email archiving software or to an email archiving service provider. Log scraping occurs when a software service actually looks at messaging, calendaring and other log file data, and it scrapes it out and puts it into the archive. No matter how the messages get in there, those are customer priorities. Different architectures and products move messages into a secondary environment differently, but those are the two most common.
Stubbing messages after messages are in the archive. You tend to have a copy in the primary inbox and then one in the archive. If you have that copy in the secondary archive you can actually create a link and remove the first copy. So now you're only storing one copy of the message, and you have a "stub." That preserves access, and even though the message is in the primary inbox you can still access it via the stub or the link because the message is being stored in the archive itself. This is where the storage cost/savings comes into play. If you're doing mailbox grooming, scanning messages that are older than 30 days so you can move them out to a secondary environment, during that scanning process is when a stub is left as the messages are moved over to the secondary environment.
So it's key to understand that stubbing really is a benefit because it reduces storage costs, while log scraping and journaling are methods used to get messages into an archive.
Go back to the beginning of the Email Archiving in 2008 FAQ Guide.