v3.2
This is a difficult question to answer I think, and the solution probably requires extensive database manipulation...
When I set our site up and imported all the users, I didn't really know about the message preferences and notification preferences.
The defaults in 'Site administration ► Plugins ► Message outputs ► Default message outputs' are no good for our institution, so now I can't enable messaging or notifications until they are changed for every user. Most of the settings also need to be set to 'locked' so the user cannot change them.
There are also a couple of settings in 'Dashboard ► Preferences ► User account ► Message preferences' too, and I need to be able to turn email to off, and also lock that setting.
One further problem I have is that I do not have access to the server or database myself. This request is something that I will have to pass onto a busy technician, who will probably just run any given queries without looking at it too deeply, and not really be invested in the problem is something breaks.
I was half hoping that these settings could be reset by simply downloading a CSV file of users, and re-importing it using the 'overwrite' setting. That would be brilliant if the 'message outputs' settings would be re-applied during that process, but I don't think they would be.
Thanks.