EnvelopeCat is a simple and easy-to-use app for printing address onto envelopes on the Mac. It integrates nicely with Address Book to allow you to print a single address or a whole batch of envelopes. Of course you can use the records from Address Book but you can also enter in your own addresses from scratch.
Print a single envelope with a stunning interface or even print an entire batch of them, you have rich sorting and a quick search at your use. When printing a singular envelope you can simply press the print stamp on the envelope to print the current envelope, it couldn't be more simple!
Note: Now requires OS X 10.11 or later