Proton Mail is one of the best alternatives to Gmail, Outlook, and Apple Mail out there, with end-to-end encryption, tracker blocking, and phishing protection among the features on offer. A free account gets you 1GB of storage and up to 150 messages per day.
The latest feature to be added to Proton Mail is the option to hide your email address: That’s where you set up an email alias to provide when you buy something or sign up for a social media service, while keeping your actual email address private. It’s something already available on other email clients (like Apple’s), and you can get it set up in just a few minutes.
If you’re on a paid Proton Mail plan, you can create as many email aliases as you like, while free account users get up to 10 of them.
I like to keep track of every e-mail alias I create, as it gives me a clue as to who has passed my mail address onto others who end up spamming me.
Note if you have your own e-mail domain name, you can often use a catch-all function which lets you create as many, and any, mail addresses you want to at no extra cost. An advantage of this method is, the addresses can follow you no matter what back-end mail provider you switch to in future.
See https://lifehacker.com/tech/how-to-set-up-email-aliases-proton-mail