Digest email not to be sent to new users

I am using discourse as my sso provider for my android application and wordpress website. So new users for my situation is a little different than new users of a normal discourse forum.

In a normal discourse forum, a user comes and reads some topics, enjoys the forum a little bit and creates a profile to enjoy it even more. So in normal situations, new users are engaged with the forum a little bit already and sending digest emails to them would be indeed beneficial.

However in my design, a new user might not be a new user for discourse forum. it might be a new user for the application or wordpress website, which could have zero interest in the forum. And even they might not know that there is a forum. And I’m pretty much sure that sending digest email to a user that doesn’t have any Idea about the forum is not really beneficial.

on the other hand, I don’t want to lose the opportunity of sending digest emails. So I think the best option for me is to send digest emails to tl1 members and above.

Can you explain this part to me a little bit? I didn’t understand it. What should I do?