We've not made any changes to the way nopCommerce processes emails.
Until we fix and deploy this, I just want to clear things up. In the customer reminders plugin, we do not take into account the IsActive
property of the message templates, because we want to make sure that the emails will be sent always. But I admit that it is a bad customer experience to reset the IsActive value when a reminder is saved. So as I said in my previous answer, we will fix it asap.
About the sending emails twice. In our plugin we just queuing emails. It is the nopCommerce that sent the emails. So if there is only one queued email, but your customers are receiving more than one emails, then the problem is not in our plugin.
In the end, I would like to explain that the number of items in the shopping cart does not reflect on how many emails would be sent. If, for example, there is a customer with 5 items in the shopping cart - only one email is going to be sent. When he adds another item in the cart and reminder's requirements are met, an email would be sent on the next scheduled task cycle.
Hope this helps!
If you have any further questions, please do not hesitate to ask!