Cheat Sheet: Distribution Lists - Project v.s. Document

You can add or remove Users from Distribution lists at the Project level (under Team):

And on each document:

Here is the difference between both Lists:

Removing a User from the Team Distribution list will only remove them from the list of eligible Users to distribute documents. They will continue receiving email notifications if they remain in document Distribution lists. 

To stop email notifications, remove the User from the Document's Distribution list.