Sent. File Demo 

http://sentapi.com/index.php/api

Your API url:

The form

This form includes an file upload field. The uploaded file will be attached to the email by the Sent API.

Please enter an email address to which the form data should be send:

Select file   Change   Remove

The code

<form method="post" action="//yourdomain.com/api/[email protected]" method="post">
    <input type="hidden" name="_valid[name]" value="required">
    <input type="hidden" name="_valid[email]" value="required|valid_email">
    <input type="hidden" name="_valid[message]" value="required">
    <input type="text" name="name" placeholder="Your name">
    <input type="email" name="email" placeholder="Your email">
    <textarea  name="message" rows="3" placeholder="Your message"></textarea>
    <button type="submit" class="btn btn-primary btn-embossed disabled">Submit Form</button>
</form>