When you send mail using an SmtpClient object
(System.Net.Mail.SmtpClient), the headers it adds like "from:", "to:"
and "date:" are in lower case. This seems to be a red flag to some spam
filters, so it would be good to be able to specify that they be
proper-cased, i.e., "From:", "To:" and "Date:".
Also the date format used doesn't include the weekday, e.g., "31 Mar
2006 07:25:10 +1200" instead of the more common "Fri, 31 Mar 2006
07:25:10 +1200" which is also a red flag to some spam filters, and so
it would be good if it used the latter.