How to delete corrupted and hidden rules from a single mailbox in Outlook 2003

Download MFCMapi to a folder on your computer.

The following file is available for download from the Microsoft Download Center:
Download the MfcMapi.EXE package now.
Open the folder to which you downloaded the MfcMapi.exe file, and then double-click MfcMapi.exe.
In the Choose Directory for Extracted Files box, type the path of the folder in which you want to save MFCMapi, and then click OK. For example, save MFCMapi in a folder that is named C:\MFCMapi.
Copy any rules that you created in Outlook. To do this, follow these steps:
On the Tools menu, click Rules and Alerts.
In the Rules and Alerts dialog box, click Options.
In the Options dialog box, click Export Rules. Note the location where you save the rules.
Use MFCMapi to remove all rules that are applied to the mailbox. To do this, follow these steps:
Open the folder to which you extracted MFCMapi, double-click mfcmapi, and then click OK.
On the Session menu, click Logon and Display Store Table.
If you are prompted to select a profile, click the profile name in the Profile Name list, and then click OK.
Double-click the mailbox that contains the inbox rules that you want to delete.
Expand Root Container, and then expand Top of information Store.

Note Outlook should be in Online mode to use MFCMAPI. If you see IPM_SUBTREE instead of Top of information Store, Outlook Cache mode is enabled. Disable Outlook Cache mode before you use MFCMapi.
Right-click Inbox, and then click Open Associated Contents Table.

The Open Associated Contents Table contains the hidden messages of the Inbox.
In the Inbox window, locate and then click the items that have the IPM.Rule.Message message class, and then click Delete.
Select Permanent delete passing DELETE_HARD_DELETE (unrecoverable) in the drop-down list, and then click OK.
Import the backed-up rules into Outlook. To do this, follow these steps:
On the Tools menu, click Rules and Alerts.
In the Rules and Alerts dialog box, click Options.
In the Options dialog box, click Import Rules.
Locate the rules that you copied in step 4, click Open, and then click OK.