INT 16 - Shamrock Software EMAIL - GET STATUS
        AX = 4500h
        DL = port number (01h = COM1)
        ES:BX -> 13-byte buffer for ASCIZ name
Return: AX = 4D00h if EMAIL installed on specified port
            ES:BX -> "" if no connection
                  -> "*" if connection but caller has not identified name
                  -> name otherwise
            CX = version (CH = major, CL = minor)
            DL = privilege level of user (00h = guest)
            DH = chosen language (00h German, 01h English)
SeeAlso: AX=4502h