JSFiddle - React, Tailwind, and code Playground

JavaScript

function cev(email) 
{
 if (/^[a-zA-Z0-9.!#$%&'*+/=?^_`{|}~-]+@[a-zA-Z0-9-]+(?:\.[a-zA-Z0-9-]+)*$/.test(email))
  {
    return email + ": valid";
  }
    return email + ": not valid";
}

console.log("valid");
console.log(cev("firstname+lastname@example.com"));
console.log(cev("email@example.museum"));
console.log(cev("firstname-lastname@example.com"));
console.log(cev("email@123.123.123.123"));
console.log("invalid");

console.log(cev("#@%^%#$@#$@#.com"));
console.log(cev("email@-example.com"));
console.log(cev("email@example..com"));
console.log(cev("Abc..123@example.com"));
console.log(cev("email..email@example.com"));