2-color printing means that it can print two colors (typically black plus one color).

4-color printing allows you to print on envelopes in full color.

Adding postal barcodes to your mail gives you access to the best postage rates and helps your mail move faster through the postal system.

Some addressing systems allow you to import Graphics and print them directly onto envelopes.

Address management software helps you manage and prepare your address lists for mailings. Includes features to save on postage costs.

List analysis software allows you to add additional demographic and other data to your addresses to create valuable marketing reports.