You can use this modification to export your Zen Cart newsletter subscribers (and others)
list to a CSV or TXT file for easy import into an email program's address book.
Thus, you can use a 3rd-party emailing tool for sending your advertising newsletters, etc.

Zen cart 1.3.9, 1.5.0, 1.5.1, 1.5.3, 1.5.4, 1.5.5+, 1.5.6+