+ 3
There are several ways to achieve what you want (some more effective than others). In any case I'll leave you three alternatives.
1. The traditional: you can use PHP to send an email: https://www.w3schools.com/php/php_ref_mail.asp
2. The not so common: it can be sent with JS in a simple way. It has its drawbacks, but this thread delves into it (in the first response): https://stackoverflow.com/questions/271171/sending-emails-with-javascript
3. The one that uses APIs: you can use the API of some mail service and make use of its qualities (see messages / send them). But I do not recommend using this in CodePlayground since it implies the use of KEYS that must be private, however I leave an article in an informative way: https://www.sitepoint.com/sending-emails-gmail-javascript-api/