wp-calypso/packages/help-center/src/icons/mail.tsx

const Mail = () => {
	return (
		<svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24">
			<path
				d="M18 6.75H6C5.30964 6.75 4.75 7.30964 4.75 8V16C4.75 16.6904 5.30964 17.25 6 17.25H18C18.6904 17.25 19.25 16.6904 19.25 16V8C19.25 7.30964 18.6904 6.75 18 6.75Z"
				stroke="#fff"
				strokeWidth="1.5"
				fill="transparent"
			/>
			<path d="M5 7L12 13L19 7" stroke="#fff" fill="transparent" strokeWidth="1.5" />
		</svg>
	);
};

export default Mail;