Loss Prevention and Identities
Windows Mail takes a significant step forward when it comes to addressing the shortcomings of Outlook Express in the area of mail corruption and loss. Once again, the chief contributor to that effort is the major player of the new architecture: JET.
Because the JET database enables the storage of e-mails as individual files, a major point of failure is avoided. In Outlook Express, the corruption of the single Inbox.dbx file typically meant the loss of everything in it. Now, however, the corruption of any single mail file doesnt mean the loss of integrity of any and all mail, but rather only the single message.
Or does it?
A few surprise bells and whistles are working in the background of Windows Mail to keep order in the area of disaster recovery. In fact, there is a layered approach to the mitigation of corruption and loss. First, there is the fact that the new database is fully transactional. This means when messages are deleted, you can play back the transaction logs to re-create the full picture. For example, if youre about to save a message and you lose power, the transaction logs will roll back to the point of failure. Second, the database can be reconstructed from the files themselves, so the loss of the database is only a minor hit. Lastly, an actual backup database is kept up-to-date with everything that takes place within the primary mail database. This database file is an exact replica of the primary one, and is located at C:Users
In the event of corruption to any of the three sources (primary message database, backup database, or log files), the OS uses the other two to rebuild the third automatically. This establishes a very sound and stable environment for users, even those in business settings where locally stored mail cannot be lost to corruption.
Now, if youve been in the business of mail management, you know the obvious problem with the preceding statement is that corruption is only one way to lose data; disk loss is another. How does Windows Mail handle the backing up and restoring of mail and associated accounts? The answer is much differently than Outlook Express.
In Outlook Express, the account information that tied the .dbx files to real users was kept in the Registry. This presented two problems. First, there were now two groups of data to back up: a series of .dbx files, and then a series of Registry entries for both the mail and news accounts that are stored in the Registry key HKEY_CURRENT_USERSoftwareMicrosoftInternet Account Manager.