This feature is not presently implemented but will be available in a feature release of the software. However, the program, in its present form prints the vendor's address at the bottom of the PO.  This enables the PO to be placed into windowed business envelope.

Additionally, you can select an option on the Purchase Order Printer dialog box which moves the shipping address to the right slightly and includes your return address.  This allows the PO to be slipped in a double-windowed envelope

Additionally, you can copy the vendor's address to the Windows Clipboard.  To put the address in the clipboard, select EDIT from the Menu Bar and choose ADDRESS COPY & PASTE >> COPY ADDRESS TO CLIPBOARD or COPY SHIPPING ADDRESS TO CLIPBOARD.