When you rebuild your Windows Mail store - which is simply the location where your Windows Mail folders are stored - any corrupted files will be removed and your email messages that are not corrupted will be loaded back into your Windows Mail folder.

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Start by locating your Windows Mail store. Open Windows Mail, go to Tools and select Options. Go to the Advanced tab and click the Maintenance button. Click the Store Folder button. A Store Location window will open, displaying the file path of your Windows Mail store. Highlight the location with your mouse and copy the file path by right-clicking and selecting Copy or using the keyboard shortcut Ctrl+C. Click OK to close the Store Location dialog and close the remaining dialog boxes, as well as your Windows Mail application.
Click the Start button and paste the Windows Mail store location into the Start Search box. Press Enter. The folder containing your Windows Mail messages will open.
If you would like to backup your Windows Mail folder prior to rebuilding your Windows Mail store, go to the desktop, right-click, point to New and select Folder. Name the folder Windows Mail Backup and double-click to open it. Go back to your Windows Mail store folder, select all of its contents and copy them. Return to the new desktop folder and paste the Windows Mail store copies inside.
In your original Windows Mail store folder, right-click WindowsMail.MSMessageStore and then click Delete. (If you have any trouble deleting it, restart your computer in Safe Mode and try again. For instructions on using Safe Mode, read How To Use Windows Safe Mode.)
Double-click the Backup folder in the Windows Mail store, and then double-click the New folder. Use the keyboard shortcut Ctrl+A to select all of the files in the New folder. Press Delete.
Close all of the open folders. Start Windows Mail to see if your corrupted folder has been repaired. If so, congratulations! If not, move on to the next step.