I’m confused by this
Seems to me that if a member is logging in, then they are engaging.
Anyway, there is Admin-> Settings → User Preferences
default email always [default: not checked]
Send an email notification even when the user is active by default.
But AFAIK that is not the same as the Profile Setting
Activity Summary
When I don’t visit here, send me an email summary of popular topics and replies
IMHO the nicest way would be to ask members to uncheck that option.
The potentially more aggravating way would be to use the CLI to check it for members without their explicit agreement.
*Warning. by some definitions getting unsolicited emails is considered to be SPAM
Getting the forum onto a blacklist is most likely something you want to not happen.