Available Headers in the SPEmailMessage Object

It couldn't find a complete list of email headers for Microsoft.SharePoint.Utilities.SPEmailHeader, so I've compiled one here;

Here's a sample usage that will return the raw email address of the sender...
// emailMessage is of the type SPEmailMessage
string EmailAddress = emailMessage.Headers["Return-Path"].ToString();
// will return "sender@domain.com"

string EmailAddress = emailMessage.Headers["From"].ToString();
// will return "Sender Contact Name <sender@domain.com>"

Ordinal	Name	Example
1	x-reciever	"recipient@domain.com"
2	Received	"from IncomingMailServer([IP])..."
3	Received	"from IncomingMailServer([IP])..."
4	From	"Sender Contact Name <sender@domain.com>"
5	To	"Recipient Contact Name <recipient@domain.com>"
6	Subject	"Subject Text"
7	Thread-Topic	"Topic Text"
8	Thread-Index	guid
9	Date	ddd, dd mmm yyyyy hh:mm:ss +0000
10	Message-ID	"UniqueId@IncomingMailServer"
11	Accept-Language	"en-US"
12	Content-Language	"en-US"
13	X-MS-Has-Attach	"yes" or ""
14	X-MS-TNEF-Correlator	""
15	x-originating-ip	"[IP]"
16	Content-Type	??
17	MIME-Version	"1.0"
18	Return-Path	"sender@domain.com

Here's a handy way to parse out the date...
DateTime sent = DateTime.Parse(emailMessage.Headers["Date"]);