82JU-015
Where to Connect the Telephone Line
Connect the telephone line to the telephone line jack 
.
.MF746Cx / MF744Cdw / MF657Cdw / MF645Cx
MF553dw / MF543x
MF455dw / MF449x / MF445dw
When connecting an external telephone or an optional handset,
To the jack on the machine
When connecting an optional handset: Connect the telephone line from the handset to the handset jack 
on the machine.
on the machine.When connecting an external telephone or an answering machine: Connect the telephone line from the telephone to the external telephone jack 
on the machine.
on the machine. MF746Cx / MF744Cdw / MF657Cdw / MF645Cx
MF553dw / MF543x
MF455dw / MF449x / MF445dw
If you connect an external telephone with fax functionality, disable the automatic fax receive settings on the telephone.