Mass action triggering 2 emails instead of 1

Hi,

You should remove the category selection and put back "any category" so that filter only target that one product.

Besides that I tried reproducing the problem on my end and it worked fine.

Hi,

I suppose that the problem is with your tests.
You must use the same user account for your tests.
What these mass actions mean is:
"When one of the orders of a customer is confirmed, add his email to the queue if he bought the product XXX between then dates AAA and BBB".
So basically, if the customer already purchased the other product, the mass actions will both match and he will get both emails.

Instead of having the mass action add the email to the queue, you should add the customer to a list, and configure a campaign on that list with an email to be sent immediately.
That way, the customer will only receive the email the first time he purchase a product and never after that.