If you want to use your Brother machine to send and receive faxes over MagicJack, we recommend you contact MagicJack and ask them which modem speed they recommend for faxing.
Set the Brother machine's modem speed to their recommendation
Follow thease steps:
Press (Settings)
Press All Settings.
Swipe up or down, or press Up or Down arrow key to display Initial Setup.
Press Initial Setup.
Swipe up or down, or press Up or Down arrow key to display Compatibility.
Press Compatibility.
Press High, Normal, or Basic (for VoIP).
High sets the machine's modem speed to 33,600 bps.
Normal sets the machine's modem speed to 14,400 bps.
Basic (for VoIP) sets the machine's modem speed to 9,600 bps.
If you change the Compatibility to Basic (for VoIP):
The machine will print all received faxes in black and white.
The Error Correction Mode (ECM) feature will only be available for color fax sending.