<form id="RMAForm">

    <input id="Kundenavn" type="text" value="@Model.InvoiceDetailsSingelLine.Kundenavn">

    <input id="Ordrenummer" type="text" value="@Model.InvoiceDetailsSingelLine.Ordrenummer">

    //id
    <input id="RMAID" type="hidden">

    </form>

<script>
    $(document).ready(function () {

        $("#btn").click(function (e) {

            e.preventDefault();


           var kundenavn = $("#Kundenavn").val();
           var ordrenummer = $("#Ordrenummer").val();
           var id = $("#RMAID").val()


            $.ajax({
                type: 'POST',
                url: "/xxx/ProcessRequestRMA",
                dataType: 'json',
                data: {
                    kundenavn: kundenavn,
                    ordrenummer: ordrenummer,
                    id:id

                },

                success: function (status) {

                    if (status == null) {

                        status.Kundenavn = kundenavn;
                        status.Ordrenummer = ordrenummer;

                        console.log('Send');
                    }


                },

                error: function () {
                    console.log('something went wrong - debug it!');
                }
            });

        });


    });
</script>

[HttpPost]
    public JsonResult ProcessRequestRMA(int? id, string kundenavn, string ordrenummer)
    {
    //SAVEING INTO DataBase


        var SaveDb = db.RMA_History.Where(a => a.Id == id).FirstOrDefault();

        if (SaveDb == null)
            db.RMA_History.Add(new RMA_History
            {
                Kundenavn = kundenavn,
                Ordrenummer = ordrenummer,
            });

        db.SaveChanges();

//SENDING MAIL
        RMA rma = new RMA
        {
            Kundenavn = kundenavn,
            Ordrenummer = ordrenummer

        };
            var SubjectOne = "RMAAJAX";
            var SendTo = "someemail@email.com";
            var errorMessage = "";

            try
            {
                // Initialize WebMail helper
                WebMail.SmtpServer = "smtp;
                WebMail.SmtpPort = 25;
                WebMail.UserName = "someemail@email.com";
                WebMail.Password = "";
                WebMail.From = "someemail@email.com";
                WebMail.EnableSsl = true;
                WebMail.SmtpUseDefaultCredentials = false;


                // Send email
                WebMail.Send(to: SendTo,
                    subject: SubjectOne,
                    body: "Kundenavn" + kundenavn + "<br>" + "ordernummer" + ordrenummer + "<br>"

                    );

            }
            catch (Exception ex)
            {
                errorMessage = ex.Message;
            }




        return Json(rma, JsonRequestBehavior.AllowGet);
    }