C# 输出字体格式

public void RequestDatasheets(string partnumber)
        {
            string mailto = "mailto:[email protected]";
            string subject = "?subject=Request Datasheet -" + partnumber;
            string body = "&body=Hi,Dear marcom:"+Environment.NewLine+"  i want to xxxx";            System.Diagnostics.Process.Start(mailto+subject+body);
        }请问怎样改body的字体格式，现在默认的是宋体，怎样改成Arial！