Can't print an envelope on my Brother printer (MFC-7840W) from Libreoffice (4.4.1.2) on my iMac (10.12.3).

Can’t print an envelope on my Brother printer (MFC-7840W) from Libreoffice (4.4.1.2) on my iMac (10.12.3). Envelope goes through eh printer but isn’t printed. On the print screen, the image of the envelope with addresses is correct But on the left side of the screen is an envelope in the vertical position with the return address only in one corner perpendicular to the normal orientation.