Re: enable email but disable email change.

GF wrote :
> IS there any way for doing what I need (apart modifying brutally the
> specialPreferences.php?

I would suggest to add the appropriate Hook (http://www.mediawiki.org/wiki/Hook) in LocalSettings.php.

Someone with more experience with hooks and SpecialPreferences.php might tell you which hook to use.

my guess would be the "InitPreferencesForm" Hook (with something like $foo->mUserEmail =
$wgUser->getEmail(); )