Dont overcomplicate email, Its basic.

you can just use a mailto link, thats pretty much what the other email libraries use, heres how to do it in html

<a href="mailto:[e-mail]">send a email</a>

email library services exist to make you pay, it even works for advanced features, and its not that advanced! Theres even a js for https://cdn.jsdelivr.net/npm/validator@13.15.15/validator.min.js , Just learn how to do it in a email client, and if so please dont fall for this lie. Use WebDriverIO for automation, Deno for server side, and even use TrackEvent in JS