Mandrill "reject_reason":"unsigned"
<p>I'm trying to send emails using mandrill email service but I get the following error:</p>

<pre><code>[
    {
        "email": "pranav_withyou@hotmail.com",
        "status": "rejected",
        "_id": "daab0daa538a4fe9b161be709593be0b",
        "reject_reason": "unsigned"
    }
]
</code></pre>

<p>I am trying to send email using ajax call in javascript like :</p>

<pre><code>    $.ajax({
        type: "POST",
        url: "https://mandrillapp.com/api/1.0/messages/send.json",
        data: {
            "key": "RemovedforSecurityitscorrect",
            "message": {
                "html": "&lt;p&gt;Example HTML content&lt;/p&gt;",
                "text": $('#emailText').val(),
                "subject": $('#emailSubject').val(),
                "from_email": $('#fromEmail').val(),
                "from_name": $('#fromName').val(),
                "to": [{
                        "email": $('#toEmail').val(),
                        "name": $('#recipientName').val(),
                        "type": "to"
                }],
                "headers": {
                    "Reply-To": $('#fromName').val()
                }
            },
            success: function (data) {
                console.log("Email Sent");
            },
            error: function (xhr, status, error) {
                console.log("Error while sending mail");
            }
        }
    });
</code></pre>

<p>all values are coming to ajax call &amp; call is made to server evident from response. What can be issue?</p>