Thank you for sharing your experience with the plugin. I am sorry to read it was a negative one.
From what you have written, I can see that the plugin worked without a problem for 6 months. If the emails “suddenly stopped” arriving then something on the website or in the email system has changed.
Do you know if you / someone from your team changed something since this was working? Maybe updated a plugin, a theme or something else? Or even changed something in the email system? Usually by tracing back what has changed you can find the source of the problem.
One thing I’d like to point out that the plugin cannot “just stop sending emails”. Delivery of emails depends on a lot of factors, and based on my experience, 99% of the issues are caused after the email left the website, so it is not something we can control.
You can check if the plugin is sending an email by installing a plugin such as Email Log. If you can see the email in the log, then the plugin is doing its job and we can’t do more than that.
I hope the above helps. Should you have any questions or you want us to assist you, please let us know.
Have a great weekend!