Brother MFC-5440CN - Manual (Page 166)

APPENDIX A A - 10
Connecting an external telephone answering
device (TAD)
Sequence
You may choose to connect an additional answering device.
However, when you have an external TAD on the same telephone
line as the MFC, the TAD answers all calls and the MFC “listens” for
fax calling (CNG) tones. If it hears them, the MFC takes over the call
and receives the fax. If it does not hear CNG tones, the MFC lets the
TAD continue playing your outgoing message so your caller can
leave you a voice message.
The TAD must answer within four rings (the recommended setting is
two rings). The MFC cannot hear CNG tones until the TAD has
answered the call, and with four rings there are only 8 to 10 seconds
of CNG tones left for the fax “handshake”. Make sure you carefully
follow the instructions in this guide for recording your outgoing
message. We do not recommend using the toll saver feature on your
external answering machine if it exceeds five rings.
If you do not receive all your faxes, reduce the Ring Delay
setting on your external TAD.
If You Subscribe to your Telephone Company’s Distinctive Ring
Service:
You may connect an external TAD to a separate wall jack only
if you subscribe to your telephone company’s Distinctive Ring
service, have registered the distinctive ring pattern on your
MFC, and use that number as a fax number. The recommended
setting is at least four rings on the external TAD when you have
the telephone company’s Distinctive Ring Service. You cannot
use the Toll Saver setting.