You can append to your existing e-mail address in various ways, and this could be pretty useful for seeing who leaked your e-mail address to spammers. For example, for your bank, give them the address myaddress+banking@gamil.com. Then, if spammers send to that address, you can quickly see where they got the e-mail address from!
I've tested it with Proton Mail, and it works in exactly the same way.
See
Your Gmail Account Has Unlimited Addresses#
technology #
email #
antispam #
privacy 
Your Gmail can be used over and over again, with no one the wiser.
