8150 all envelopes wringle

[Mbates]

I deal with 5 HP 8150 that have all the options including 2000 Input tray as well as a envelop feeder. Envelopes in all printers wrinkle on the back edge, not the leading edge, no matter how many are place in the feeder. Any assistant is this will be gratefully appreciated.
Thank
MBates

[Brian]

It's very likely that there is air in the envelopes, this can't get out so you get wrinkles on the back edge.

[hai]

Set the two tension levers of the fuser to the UP position when running envelopes then you're good to go.