Hi @Marc Stridgen
I am sorry but in fact, my members still report a problem.
In addition to my admin account, I have created another "normal user" account to test everything out.
With my testing account, I do receive an notification email when I tagged this account in a topic.
However, yesterday evening, my members told me they did not receive any notification email even if I had tagged them.
I don't understand why.
Do you have any idea/suggestion?
Best regards