Brother MFC-8640D - Manual (Page 22)

1 - 15 USING THE MACHINE AS A PRINTER
6
Press and slide the paper-width guide to fit the envelope size.
7
Send the print data to the machine.
8
After you finish the print job, close the back output tray.
When you put envelopes in the MP tray, please remember the
following:
■ During printing, the inside tray rises to feed envelopes into
the machine.
■ The side to be printed on must be face up.
■ Put the leading edge (top of the envelope) in first and push
it gently into the tray.