Snail Mail is a stand-alone app that addresses and prints very nice envelopes based on the information in your Address Book (See an earlier Hawk Wings review).
It can print single envelopes or an envelope for every member of an Address Book Group. You also select multiple cards for printing on the fly.
An updated version released today (1.5) is a universal binary.
It also supports the swapping of first and last names, easier removal of a return address and a preference to omit the delivery country if it is the same as the return address country.
Snail Mail is donation-ware and is available from the developer’s web site .
Tags: Address Book, envelopes, helpful apps, Productivity