If you wish to disable a rule temporarily, rather than deleting the rule, you can mark it as disabled. You can do this in the following way:
Select Rules… from the Mail menu. The Rules dialog box is displayed. Select the rule that you wish to disable and press the Edit button. A Rule dialog box is displayed with the Details page selected.
Uncheck the Enabled check box. The rule will now be disabled. To re-enable a disabled rule, check the Enabled check box.