Whenever we run any list in List Manager, we get customers' middle initials and we want to eliminate the middle initial from the data. I don't see a way to do that. Customer mname is listed in the output elements but that seems to be something you would check if you want to include it in the output. The list includes it even when I don't select it.
Is the Middle initial in the salutation? Like Heidi Below:If so you may want to check your salutation settings.