@foreach (var item in Model)
{
    if (item.Status == "New")
    {
        <div class="panel panel-default" data-id="@item.Id"  onclick="GetMessageId()" id="clickId">
            <div class="panel-heading">
                <a class="btn btn-success" data-toggle="collapse"  href="#imageGallery-@item.Id" style="width: 100%">
                    <h4 style="color: white; text-align: left; width: auto; z-index: 3">
                        От: @Html.DisplayFor(modelItem => item.EmployeeTo.Name) -
                        <strong> @Html.DisplayFor(modelItem => item.Title)</strong>
                    </h4>
                </a>
            </div>
            <div class="panel-body collapse" id="imageGallery-@item.Id">
                <strong style="color: dimgrey">Заголовок:</strong><h5> @Html.DisplayFor(modelItem => item.Title)</h5><br />
                <div style="width: 100%">
                    <strong style="color: dimgrey">Содержимое</strong> <h4>@Html.DisplayFor(modelItem => item.Content)</h4>
                </div> <br /><hr />
                <p style="color: dimgrey">Дата отправки: @Html.DisplayFor(modelItem => item.DateFrom) </p>
                <a class="btn btn-primary" onclick="showModalSendOrderAdmin()">Переслать</a>
            </div>
        </div>
    }
}

var idMessage;
    function GetMessageId() {
        var messageId = document.getElementById('clickId');
        idMessage = messageId.getAttribute('data-id');

        $.ajax({
            type: 'POST',
            url: '@Url.Action("OrderStatus", "OrderEmployees")',
            data: {
                idMessage: idMessage
            },
            success: function (data) {
                console.log('success!');
            }
        });
    }

public ActionResult OrderStatus(string idMessage)
        {
            var messageId = _context.OrderEmployees.SingleOrDefault(m => m.Id == idMessage);
            if (messageId != null && messageId.Status == "New")
            {
                messageId.Status = "Open";
                _context.Update(messageId);
                _context.SaveChanges();
            }

            return RedirectToAction(nameof(Index));
        }