newline email body C#

I am trying to send an email using the default email client ( in C# 2005 )  in the following manner:

private void SendEmail ()
{
    string emailMessage;                // Email message to be sent
    string body;                              // Email message body
    string subject;                          // Email subject
           
    subject = Subject + "-" + ck.GetSiteCode2 ();
    body         = "Name:  "+ Environment.NewLine;
    body        += "Phone number:  " + Environment.NewLine;
    emailMessage = string.Format ( @"mailto:{0}?subject={1}&body={2}", MailTo, subject, body );
    Process.Start ( emailMessage );
}

It opens the Outlook email client with all the correct information except that body is not formatted properly.  It is showing like this:

Name:  Phone number:

and should be like this:

Name:
Phone Number:

What am I doing wrong?