Format of Da Vinci eMail command buffer:
Offset	Size	Description	)
 00h	BYTE	command
		21h '!' Protocol commands for remote control
		41h 'A' Authorization protocol element
		42h 'B' Return(back) routing information
		    Associated data is the From: username
		43h 'C' Carbon Copy list
		    Associated data is a comma delimitted list of usernames
		44h 'D' Distribution list
		    Associated data is a comma delimitted list of usernames
		45h 'E' Mail end marker
		    No associated data
		48h 'H' Mail message header
		    Associated data is a message header buffer
		4Dh 'M' Mail message
		    Associated data is the body of the message
		4Fh 'O' Object
		50h 'P' Paperclip attachment
		52h 'R' Routing information
		    Associated data is the To: username
		53h 'S' Subject
		    Associated data is the subject of the message
		54h 'T' Trail of Reply/Forwards
 01h	BYTE	subcommand
 02h	DWORD	length of associated data