There is a serious security issue with this plugin that has existed for a very long time now - bad enough for Wordfence to advise complete removal of the product. Contacting support about it several times produces nothing but weak assurances that the developer is working hard on the problem. This, unbelievably, is followed by incredibly long periods of silence.

Below, as reported by Wordfence:
----------------------------------
Plugin Name: Optinly

Current Plugin Version: 1.0.18

Details: To protect your site from this vulnerability, the safest option is to deactivate and completely remove "Optinly" until a patched version is available. Get more information.(opens in new tab)

Repository URL: https://wordpress.org/plugins/optinly(opens in new tab)

Vulnerability Information: https://www.wordfence.com/threat-intel/vulnerabilities/id/13b0f306-cfd1-4c36-b694-de7968f0ae1c?source=plugin(opens in new tab)

Vulnerability Severity: 7.1/10.0 (High)
-----------------------------

This certainly reflects badly on their reputation, and brings into question their other products' support as well.