Supported Internet Headers

[amber.webster]

Hello,

I am looking for a resource which lists what internet headers are
supported by the of Outlook 2007 and Outlook 2003. I am
programmatically sending mail via EasyMail .NET and need to make sure
the headers I use will be supported. The research I have done so far
has only turned up ways to view the headers in the email client, which
isn't what I need. Any help is greatly appreciated.

Thanks!
Amber