Lexmark All in One Printer - Manual (Page 67)

67 Loading Print Materials
Using the envelope feeder After loading envelopes in the envelope feeder, select the paper
source from your software application, and then select the paper
size and type from both your software application and from the
printer operator panel.
To set the printer operator panel:
1 Make sure the PAPER SIZE for the envelope feeder ( Env
Feeder Size ) is set to the correct envelope size you are
loading (refer to the Administrator’s Guide for detailed
information about this setting).
2 Press Go to return to Ready .
N OTE : Software settings may override operator panel
settings.
If the printer experiences an envelope jam while printing, see “260
Paper Jam Check Env Feeder” on page 96 for information on how to
clear the jam.