Please send an email to one of these addresses:
privacytoolsguide@protonmail.com (PGP Key)
If you send to the Protonmail address from your own Protonmail account your email will be encrypted by default, this is a good thing.
It is worth making a free account and get email encryption by default with almost no effort.
Alternatively you can use PGP, my public key is can be downloaded here. A guide on using PGP can be found here.
(Feel free to send from any email provider but if you can then try the using ProtonMail. It is a good learning process and introduces you to some great tools where you get a more private email system by default. Email is notoriously bad for privacy, it is like sending a postcard and therefore you have no "envelope" for protection. Email is used by Google/Hotmail etc so that their algorithms can read your email in order to sell you advertising. That is why those services are free, you are the product.)