INT 16 - Shamrock Software EMAIL - SEND RESULT OF USER FUNCTION
        AX = 4505h
        DL = port number (01h = COM1)
        DH = error flag
            bit 3: set on error
        ES:BX -> ASCIZ text to return to user, max 1024 bytes
Return: AH = 4Dh if EMAIL installed on specified port
        AL = status
            00h successful
            02h unable to perform function (timeout, prev call not complete)
            other error
Notes:  if the error flag in DH is set, the string is not sent and an error
          message is generated instead; if this function is not called within
          five seconds of AX=4504h, EMAIL automatically generates an error
          message
        the string is copied into an internal buffer, allowing this function's
          caller to continue immediately
SeeAlso: AX=4504h,INT 17/AX=2400h