Hello. I understand the printer is experiencing issues feeding envelopes. Please ensure you are completing the correct process, by referring to this HP document: http://h10025.www1.hp.com/ewfrf/wc/document?cc=us&lc=en&docname=c01763177
Applying the steps should ensure the envelope is selected, and imprinted accordingly. Please let me know your outcome. I'm only here to help!
Mario