I spent 4 hours on the phone with technical support trying to print the most common evnvelope in the world, Env #10, used for personal and office use. It holds a US Letter folded thrice. I did this knowing I was able to do so on my previous HP printer, which I was very happy with. Sadly this wonderful printer had a faulty motor. I have since received two replacement devices from the Escalations Department regarding this issue in the past week. The escalations case manager was as understanding and helpful as she could possibly be and was also in disbelief that the device wouldn't print return addresses. She worked tech support previously. It was clear she wanted to help but is not a technical specialist.
After installing the 2nd replacement, I called Total Care and requested to speak to the Technical Support Manager for the call center and gave them my case number with Escalations. I also offered to speak to the Call Center Manager if the lead technician was not available. I waited 33 minuets and got a basic supervisor. Both of my request were denied. The supervisor I spoke with wouldn't give me a last name or any contact information.
MAC USERS! There is a way! However you will not be able to print high quality designs or photos on your envelopes.
System Preferences -----> Print and Scan ------>click + ------->Select the printer, "Name: Envelope Printer" and "Use: Airprint" from the drop down menu. This will install drivers FROM APPLE and not HP. When you need to print an envelope, at the print screen select the Envelope Printer from the drop down menu. Your print screen will have a number of changes and different options which are less specific and useful. However you will have full margin printing for return addresses. I will warn, the color profile is terrible, does not match the screen colors and makes the pictures look awful.
If this doesn't work or you don't see the Airprint option, uninstall the HP software and then delete the printer in System Preferences. Load the app store and check for updates. It should locate the Apple Driver for the Airprint protocol.