We have upgraded several FS4000's with the 4020's, where the customer had the MPT mode set as First, size set to Letter, and Type set as Envelope. When they printed before, no matter what you had in the MPT, it printed. The 4020's now show the Attention light. I have set the MPT as default, and matched the paper types and sizes. Any ideas on how to resolve this?

4020's have an envelope mode. There is a lever near fuser.

Yes it does. Sorry, but the issue is on 4000s would just print no matter what you had in the tray. The 4020 beeps the attention light.

Are you familiar with this 4020 and how the envelope mode works.

Yes, but I was checking to see if anyone new a work around on this model. It does not work like the 4000. The client does not want to have to change the setting every time they change paper in the MPT. The 4000 would allow them to do this.

I feel for you to my knowledge there is no way around this. I have customer with the same problem.

I believe that the only way to accomplish this, is to add multiple cassettes. Thanks for your help!