Hello G.Dawson,
When printer envelopes the flap should be closed not open, this could be why its jamming. Please view this article on how to load envelopes.
I am using a Xerox Altalink C8145. I have my envelopes ready to go in Drawer 5 and have progammed the printer and my computer for the envelopes. I am printing our office return address on the envelopes, so I am having to open the flap and turn the envelopes around in order to get it to print from a PDF file. In the beginning, I was able to print 17 envelopes this way. And then the copier started jamming and I haven't been able to get it to stop. I have restarted the printer. Deleted and reentered jobs. Put in fewer envelopes and nothing works. It continues to jam at Area A2. Below is a picture of what it is doing. It isn't clear, in the picture, but the flap appears to be what is causing the jam.