SharePoint-hosted apps: Send Emails using SharePoint REST API

var sendEmails = function (emailCollection) {

    var oDeferred = $.Deferred(),
        email, iCounter = 0;
    // create an object for a http request
    var oHttpRequest = {
        url: "{0}/_api/SP.Utilities.Utility.SendEmail",
        type: "POST",
        contentType: "application/json; odata=verbose",
        headers: {
            "accept": "application/json; odata=verbose",
            "contentType": "application/json; odata=verbose",
            "X-RequestDigest": $("#__REQUESTDIGEST").val()
        }
    }

    oHttpRequest.url = String.format(oHttpRequest.url, _spPageContextInfo.siteAbsoluteUrl);

    // Iterate the email collections and send emails
    for (email in emailCollection) {
        oHttpRequest.data = JSON.stringify({
            'properties': {
                '__metadata': { 'type': 'SP.Utilities.EmailProperties' },
                'From': emailCollection[email].From,
                'To': { 'results': [emailCollection[email].To] },
                'Subject': emailCollection[email].Subject,
                'Body': emailCollection[email].Body
            }
        });

        try {
            return $.ajax(oHttpRequest)
                .done(function () {
                    iCounter += 1;
                    if (iCounter == emailCollection.length) // Once all the emails are send then resolve the promise object.
                        oDeferred.resolve();
                }).fail(function (xhr, textStatus, errorThrown) {
                    alert(textStatus);
                });
        }
        catch (err) {
            err.message;
        }
    }
    return oDeferred.promise();
}


// Example Email Object
var emailCollection = [];
var oEmail = {};
oEmail["From"] = "salman.malik@de.sp.com";
oEmail["To"] = "salman.malik@de.sp.com";
oEmail["Subject"] = "Test Email From Sharepoint App";
oEmail["Body"] = "It is a test email generated from Sharepoint App";
emailCollection.push(oEmail);


sendEmails(emailCollection);