The email options a user can set on the project level are great -- however rendered largely unusable by the lack of a search or filter to find the project(s) you wish to "customize". When you're part of many projects, this becomes furthermore unfeasible.
Thus, users are left with two setting options: email notifications on or off, and when to receive them. This isnt enough to control effective email delivery
I suggest that at the least, the on/off button be separated into message notification emails, late activity notifications, and others.
A step further would be to apply the rule box for custom project notifications to a user default level. I know some of these changes can be made globally on the admin level, but the reality is that the diversity of members in an organization need a diversity of email notification options.