simple-email/node_modules/slash/index.js

'use strict';
module.exports = function (str) {
	var isExtendedLengthPath = /^\\\\\?\\/.test(str);
	var hasNonAscii = /[^\x00-\x80]+/.test(str);

	if (isExtendedLengthPath || hasNonAscii) {
		return str;
	}

	return str.replace(/\\/g, '/');
};