Envelope Printer makes printing addresses a snap:
Type in the recipient's name and address
Enter a return address
Put an envelope in the printer
Click on Print
Not all printers work the same way, so we give you several standard options for printing your envelopes. You can print in portrait, landscape or laser mode, and using either a #6 or #10 envelope size. But if that doesn't suit your needs, you can create your own envelope size using our "Roll Your Own" feature. Just tell Envelope Printer where to print the address and return address, and it will place it there for you. New! You can now use the Roll Your Own feature in Landscape mode and rotate the text 180 degrees so that addresses can now be printed on envelopes inserted from the left side of the printer's feed tray.
http://www.sorcerersoftware.com/envelope.htm