Make sure that the printer is connected to a network and that the network is connected to the Internet.
Can you send or receive faxes using etherFAX?
The problem is solved.
Go to step 2.
From the control panel, navigate to:
Settings > Fax > Fax Setup > General Fax Settings.
For non-touch-screen printer models, press to navigate through the settings.
Make sure that you have the correct fax number.
Make sure that Fax Transport is set to etherFAX.
Go to step 3.
Split large documents into smaller file sizes.
Go to https://www.etherfax.net/lexmark.
If you experience failure in getting incoming faxes, then make sure that the trays and the toner cartridge are not empty.
Are your fax messages not going through? Make sure that your printer is connected to a working analog telephone service.