AJAX

var formData = new FormData(document.getElementById('emailForm'));
    formData.append("action", "sendEmail");
    // Override body to TinyMCE content
    formData.set("body", tinyMCE.activeEditor.getContent());
    formData.set("send_type", sendType);

    if (forwardedAttachments.filter(Boolean).length) {
        $(forwardedAttachments.filter(Boolean)).each(function (k, v) {
            formData.append("forwarded_attachments[]", v);
        });
    } else {
        formData.append("forwarded_attachments[]", []);
    }
    if (fileUploads.filter(Boolean).length) {
        $(fileUploads.filter(Boolean)).each(function (k, v) {
            formData.append("attachments[]", v);
        });
    }
    $(this).addClass('is-loading');
    $.ajax({
        url: 'ajax/sendEmail.php',
        type: "POST",
        data: formData,
        contentType: false,
        cache: false,
        processData: false,
        success: function (data) {
            $('#sendEmail').removeClass('is-loading');
            displayModal('success', 'Email Sent', 'The email has been sent successfully', true);
            setTimeout(function () {
                parent.window.close();
            }, 1500);
        },
        error: function (e) {
            let response = JSON.parse(jqXhr.responseText);
            if (response) {
                displayModal('error', response.title, response.message);
            }
        }
    });