You should be able to go into your rules and stop or remove it.
The mail rules you create display in the Tools > Rules view in your mail file. This view displays the existing rules, and shows the condition and action for each rule. You can edit a mail rule by right-clicking on it and opening it.
You can use a “stop processing” action when you set up mail rules, to stop the processing of all rules following the rule that contains the “stop processing” action. The “stop processing” action is especially useful when more than one rule could apply to a message, but you want execution of mail rules to stop after the first action is executed.