Select multiple mailbox types to send emails

PHP sending mail system, custom server, username, password and port. The above must be filled in correctly to send the email successfully.
<select id="d3"><br> <option value="1">126 Email</option><br> <option value="2">163 Email</option><br> <option value="3">qqmail</option><br> </select>Send email demo: http://www.sucaihuo.com/php/1003.html