gistfile1.cs

public interface IAppCookies
{
    string UserEmail { get; set; }
    DateTime? LastVisit { get; set; }
}

public class AppCookies : IAppCookies
{
    private readonly ICookieContainer _cookieContainer;

    public AppCookies(ICookieContainer cookieContainer)
    {
        _cookieContainer = cookieContainer;
    }

    public string UserEmail
    {
        get { return _cookieContainer.GetValue("UserEmail"); }
        set { _cookieContainer.SetValue("UserEmail", value, DateTime.Now.AddDays(10)); }
    }

    public DateTime? LastVisit
    {
        get { return _cookieContainer.GetValue<DateTime?>("LastVisit"); }
        set { _cookieContainer.SetValue("LastVisit", value, DateTime.Now.AddDays(10)); }
    }
}