The received wisdom is that you never send anything back to spammers, as doing so merely confirms that they have your valid email address. But perhaps you're talking not so much about spam as emails from companies you've dealt with in the past and to whom you gave your email address? In that case, reputable companies would normally not only provide an unsubscribe option on their emails to you - and would action that request. Disreputable companies would just ignore anything you send them. I'm not sure how to do what you want to do in Outlook, but I'm suspecting it would probably be a waste of time.
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