Spammers go for the easiest targets. If you do stuff like this, they might redesign their system to make it LESS likely to send to you. Keep in mind theyre targetting the elederly, mentally handicapped, and the emotionally desperate. They specifically DO NOT want to target the educated, technologically literate, and those that will waste their time. By attempting to technologically limit them from their scams, you make it more difficult for them to target you and it makes it obvious theyre not worth your time.

Its not about making yourself scam proof, its about making yourself an unappealing target.

(This all applies to scam emails, dunno if it has any effect if the goal is phishing but i would imagine so. If they can phish 5 people in the time it takes to phish you, youre no longer their target.)