Captcha for mailing lists in older OJS versions

Software Support
1

Hello,
because of Spam-Robots we want to activate Captcha for journal mailing lists (path:…notification/subscribeMailList) in OJS 2.4.4.1. Is this possible? What is the right place/file do this?

Kind regards
Guido

2

This is set in config.inc.php:

3

Thank you, this works.