Why when i send html email it looks like:

but initial page is:

Here is code:
MailMessage message = new MailMessage();
message.IsBodyHtml = true;
message.Subject = subject;
message.Body = body;
foreach (MailAddress recipient in recipients)
{
message.To.Add(recipient);
}
if (message.To.Count > 0)
{
SmtpClient smtp = new SmtpClient();
smtp.Send(message);
return true;
}
Html file contains css in head. http://pastebin.com/r5V6X4Ld
body?