About email notification timing of activities

I have created a share-only account and let others share data and folders.

I set the e-mail notification timing of the activity “every day” with this account. Actually, however, when there was a change in any of the data, mail notification arrived at about 1 hour later. Is this correct behavior?

This is also a question.
The user is linked to a certain shared folder. At this time, the activity of the shared folder is notified to the user.
I do not need activity notification of the sharing destination. I only want notifications only within my account. Is it possible to do such control?