Hi alexanderbackx, sorry for the delay in response here.
Can you please define what you mean by "notifications"? In general, communities don't send notifications to users by default, unless it's the email digests that are available across the whole network to every user. Users can subscribe to notifications from their communities, but it's not something set by default or centrally controlled.
For public communities: Muting the community means its content does not show in the Home Feed or email digests for folks who are not a member of the community. Non-members can get notifications if they're tagged in the post regardless of community mute status, so consider that aspect.
For private communities: We find that organizations usually choose to mute public communities over private communities. Private communities by nature can only show content to members.