A super easy way to delete all unwanted mail before it even reaches your inbox, no need to clean your spam or trash folder.
https://blocksender.io/
This is great because it doesn't allow any unwanted email sender to even enter your mail, those messages are simply deleted.
Gmail has great filters but no auto deletion, which in the case of cyberstalking becomes a nightmare.
Protonmail has a very cool programming internally, and you can set it to auto delete all unwanted messages.