Create a pythonscript/javascript that connects to imap and checks for suspicious messages.

[Spillmaker]

This is more for the independent person who wants to protect the closest ones.

This would be a system that connects to the IMAP-server (which any mail-service should have available).
Then it uses one of the detection methods people have suggested here to detect if the mail is A. from paypal and B. fraudalent.

If it is fraudalent, the script would instantly remove the email from the server.
Additionally one could modify the mail to include text that this may be fraudalent. One would download the copy of the mail, modify it with proper DOM, and then upload it again, making sure to prevent any accidental clicks on fraudalent links or phonenumbers.

It could also move the message to spam if thats something one wants.

Writing this in python or javascript would probably be the best since there are larger userbases, and there is also great support to make a package that could be running on a raspberry pi etc.

[Spillmaker]

This should be really simple to make, and one could constantly improve and expand the algorithm for detection.