Here is a screenshot of the current email preferences:

I propose we replace the top tickbox with a dropdown with the following options:

Enable emails from:

• All users
• Autoconfirmed users
• Admins and functionaries
• Nobody

I don't think you should hardcode the list, but do something like that:

DefaultSettings.php :

$wgEmailAccessLevels = [
  [ 'user' ],
  [ 'autoconfirmed' ],
  [ 'sysop', 'bureaucrat' ]
];

WMF standard settings:

$wgEmailAccessLevels = [
  [ 'user' ],
  [ 'autoconfirmed', 'confirmed' ],
  [ 'sysop', 'bureaucrat', 'checkuser', 'oversight' ]
];

This would allow wikis to react to their user hierarchy, for example:

$wgEmailAccessLevels = [
  [ 'user' ],
  [ 'autoconfirmed', 'confirmed' ],
  [ 'templateeditor', 'review', 'rollback' ],
  [ 'sysop', 'bureaucrat', 'checkuser', 'oversight' ]
];

Or anything like that. I'm not quite happy with this design yet, but it gives a rough idea what I intend to do. Maybe it's better to use keys and to define the order of the keys elsewhere.
Besides, how would you define functionaries in code?

I agree the list shouldn't be hard coded.

I posted on https://meta.wikimedia.org/wiki/Grants_talk:IdeaLab/Allow_users_to_restrict_who_can_send_them_email#Updates_from_the_WMF.27s_Anti-Harassment_Tools_team with a wireframe of what this could look like:

@SPoore — do you think we should ping users who participated on the idealab and the wishlist to get their input? Should we mention this on https://en.wikipedia.org/wiki/Wikipedia_talk:Community_health_initiative_on_English_Wikipedia/User_Mute_features ?

Another potential solution to this problem will be to simply have a tickbox (default TBD) to dis/allow email from non-autoconfirmed users.

On the one hand, it's a simple approach conceptwise and codewise, on the other hand, it reduces the feature flexibility. To get autoconfirmed isn't that difficult, and many wikis have groups kind of representing trusted users.

One alternative possibility to let this work like page protection (with just one action and without expire time): You define multiple levels and link them with user rights. (The simplest variant would be to hard code two levels direclty, this would simplify the approach, but I really think it isn't needed.) That way, you could configure the feature freely for a given wiki, combine it with global groups etc. and wouldn't have any complicated UI issues. Personally I think at the moment this would be a very good approach to handle this.

Related task: T178842: If a user has never triggered a logged action on a wiki, they should not be able receive emails by non-privileged users from there

Per feedback on wiki and discussions with the rest of the Anti-Harassment Tools team, we decided to change the default for new accounts to be to accept email from non-autoconfirmed email. (So, no change in the current experience/functionality.) If we need to adjust this in the future, we will re-approach the topic.

I've posted an update of all the on-wiki feedback we've received so far: https://meta.wikimedia.org/wiki/Talk:Community_health_initiative/Allow_users_to_restrict_which_user_groups_can_send_them_direct_emails#Feedback_summary_and_updates.2C_October_23

We haven't received enough feedback on the ticbox-vs.-dropdown discussion, so we will size both in estimation tomorrow and build whatever is simplest. (This most likely will mean the tickbox.)

How would the autoconfirmed restriction be managed internally? In my opinion, it should be a new user right (sendemail-restricted maybe).

@TBolliger Will this feature be on/off per wiki or should there be no config (and it will roll out on the next train)?

If this is a low-risk change, it should be in the next train to all Wikimedia wikis. If you feel this would benefit from a round of production QA, please release it only to meta.wikimedia and test.wikipedia.

Change 391342 had a related patch set uploaded (by Dbarratt; owner: Dbarratt):
[mediawiki/core@master] Allow users to prevent new users from sending them email.

https://gerrit.wikimedia.org/r/391342

@dmaza Everything I have so far is on https://gerrit.wikimedia.org/r/#/c/391342/6 I basically added an empty JS file.

Also see the email I forwarded you. :)

@dmaza: Tested out the patch, but strangely the pref disabling behavior isn't working for me locally:

Figured out the problem. See https://gerrit.wikimedia.org/r/#/c/391342/12/resources/src/mediawiki.special/mediawiki.special.preferences.personalEmail.js.

@kaldari my bad. Fixed.

Change 391342 merged by jenkins-bot:
[mediawiki/core@master] Allow users to prevent new users from sending them email.

https://gerrit.wikimedia.org/r/391342