Really, there are many reasons to run internal mailing/distribution lists and designate emails from them in some manner, such as a subject prefix. One of which is that people are less likely to sent an email to the "Staff" list if most the correspondence there is from management and about company level things, and then it's also very appropriate to reply to the email with content that addresses the request (in this case, you're wrong, don't do that) and also a rider about how this is not the appropriate place for this, and they should submit to the appropriate list/form.