I'm trying to use the API to create accounts using the mailpassword setting, so it will just send an Email with a temporary password (as explained here).
For whatever reason it refuses to work for me on MediaWiki version 1.28.1.
If I include password and retype variables, the account gets created just fine (sans the Email), so it's not a problem with authentication or any extra login requirements.
However, if I try at all to use mailpassword, the only response I can ever get is 'FAIL', with a status message of 'You need to provide a valid email address.', no matter how I give the email (or even omitting it).
I'm fairly confident that that this is not a client side error, as I've troubleshot to this point from scratch with two separate methods (using curl through PHP, and using Advanced REST Client). It absolutely is receiving everything that it needs to, but just refuses to take the email like it should, and that's leading me to believe that this could be a bug in MediaWiki itself.
I'm posting this here rather than creating a bug report, in the hope that maybe I'm just overlooking something, or that someone else can verify this is working for them correctly on 1.28.1 (to narrow it down to being something on my end).
Any help is appreciated, thanks.