Hi Jaye, The WorkForce Pro WF-3820's paper path is 8.5-inches wide, so it cannot feed a 10-inch wide envelope. The WorkForce Pro WF-7840 can feed sheets up to 13-inches by 19-inches, so you can use it to print addresses directly on larger envelopes. If an envelope has a clasp, it will not feed through the printer. The WF-7840 is currently available at Bestbuy.com (inventory levels may vary). Regards, Mark - The Epson Team.