Use a unique email address (and password) for every site and service
If you can, use a unique email address (and a unique password) for every site and service you sign up to.
You'll probably want to use a password manager to keep track of them all.
Services which support this
Your own email server
If you run your own email server, look in the documentation to see how to enable “catchall”.
The downside of this is that you will receive email sent to any address at your domain, so you could see an increase in the number of spam email messages you receive.
Gmail
You can use a “plus” sign after your username, and then any text you want, to create a unique email address.
For example, if your email address if johnsmith@gmail.com, you could use johnsmith+facebook@gmail.com to create a unique email address to give to Facebook.
You will still receive any email sent to that address at your normal account.
ProtonMail
You can use a “plus” sign after your username, and then any text you want, to create a unique email address.
For example, if your email address if johnsmith@protonmail.com, you could use johnsmith+facebook@protonmail.com to create a unique email address to give to Facebook.
You will still receive any email sent to that address at your normal account.