Format of Da Vinci eMail "NetOpen" parameter block:
Offset	Size	Description	)
 00h	WORD	operation (1 = read, 2 = write)
 02h	WORD	segment of uppercase To: username
 04h	WORD	offset of uppercase To: username
 06h	WORD	segment of "DVSEMAIL"
 08h	WORD	offset of "DVSEMAIL"
 0Ah	WORD	segment of node address
 0Ch	WORD	offset of node address