Change new users defaults (e.g. private email)

Hi there,

in my cloud instance, there is no wish to share the mail adress to other users.
So new users shall always have their mail adress private.

Were would i set the default mail to private?
Any Option?

  • Any Option Setting?
  • is there a set of defaults to change?
  • if not, wich line in wich php-file would i have to change to chang this default?
  • (how) could i just force mail=private to every user?

Appreciate your help