Thanks for the reply Gmayor.
The issue is that the user has several documents where the envelope section is all over the place. Sometimes it's in the middle of the document or it's at the end. What I'm trying to figure out is if Word is smart enough to take paper from the manual feed tray (always opened) to print envelopes and then to take paper from the main tray for letter pages.
Otherwise that would mean the user will need to edit all the document to put all envelope sections to the beginning of the
document.
I've already tried setting the first 3 pages in section 1 to Tray 1 and Tray 2 and the envelope section at the end of the page to Manual feed. Once I send it to the printer, it starts to print on from the manual feed.