Brother MFC-8820DN - Manual (Page 170)

USING THE MFC AS A PRINTER 11 - 13
5
After the printed envelope comes out of the MFC, the MFC will
wait until you put in the next envelope. Repeat Step 4 for each
envelope you want to print.
6
Send the print data to the MFC.
7
After you finish the print job, close the back output tray.
For MFC-8820D and MFC-8820DN:
2
Open the back output tray, and then unfold the face-up output
tray support if necessary.
3
Open the MP tray and lower it gently.
4
Pull out the MP tray support flap.
If envelopes are creased after they have been printed:
At the back of the MFC, open the back output tray and push
down the blue tabs at the left and right hand sides (as shown in
the figure on the next page). When you have finished printing
your envelopes, close the back output tray to reset the two blue
tabs back to their original position.