Build a "hide my email" functionality similar to Apple mail hide my email.
This allows users to create additional email addresses that forward to the main email address. Users can turn off and/or delete the additional email addresses at any time. This allows users to sign up for various accounts with additional email addresses and they will be able to tell from what accounts they signed up for they are receiving spam from. It helps with being able to control the amount of spam you are getting as well as being anonymous when signing up for things on various websites.