Lexmark MX532
Fuser grade issue is seen in the following conditions:
Check for the existence of non-genuine Lexmark supplies* or refilled cartridges. Use the online authentication tool to verify whether you have a Genuine Lexmark cartridge.
Check the Paper Type, for the media loaded in the printer's paper tray.
Check the Paper Weight for the type of media selected.
Confirm whether the media meets the approved paper specifications.
This is found in Paper and specialty media guide of the printer's User Guide.
LEGACY ID: SO8567
Poor Fuse Grade Issue when Using Plain/Light/Smooth Media Settings
If the quality of the faxes that you received is poor, then make sure to fix any print quality defects.