xxxxxxxxxx
<form>
<input type="email" required /> <br />
<input type="submit" value="Submit Now!">
</form>
xxxxxxxxxx
<form>
<input pattern="/^[a-zA-Z0-9.!#$%&'*+/=?^_`{|}~-]+@[a-zA-Z0-9-]+(?:\.[a-zA-Z0-9-]+)*$/" required />
<br />
<input type="submit" value="Submit Now!">
</form>