@Html.TextBox("subject", TemplateData[0], new { @class = "form-control" })

<div class="form-group">
Template: <br />
@Html.DropDownList("templateName", null, htmlAttributes: new { @class = "form-control" })
</div>

<div class="form-group">
Subject:<br />
@Html.TextBox("subject", TemplateData[0], new { @class = "form-control" })
</div>

<div class="form-group">
Body:<br />
@Html.TextArea("body", TemplateData[1], new { @class = "form-control" })
          </div>

public ActionResult SendMail(int id, string templateName)
{
    string[] templateData = new string[] { "" };
    if (!String.IsNullOrEmpty(templateName))
    {
        templateData = new string[] { db.Templates.Where(c => c.templateName == templateName).First().subject,
            db.Templates.Where(c => c.templateName == templateName).First().Body };
        }
    ViewBag.contactemail = db.Identifiers.Where(c => c.ID == id).First().contact;
    ViewBag.emailAddress = new SelectList(db.EmailAccounts, "emailAddress", "emailAddress");
    ViewBag.templateName = new SelectList(db.Templates, "templateName", "templateName");
    ViewBag.password = new SelectList(db.EmailAccounts, "password", "password");

    return View(templateData);
}