Lexmark CX730
The trays automatically detect the size of plain paper. For specialty media like labels, card stock, or envelopes, do the following:
From the home screen, touch Settings > Paper > Tray Configuration > Paper Size/Type > select a paper source.
Set the size and type of the specialty media.
Learn the correct way of loading paper into the multipurpose feeder.
This article shows the primary information required to escalate media issues.