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 home screen, touch Settings > Fax > Fax Setup > General Fax 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.