Is it possible to change / reset a user’s password via email?

Yes, it is possible to change or reset a password.

Please check our official documentation on how to reset user passwords using Server API: Users. And check the “Users” section of our official documentation for each SDK:
iOS SDK - Users | iOS SDK | QuickBlox
Android SDK - Users | Android SDK | QuickBlox
JavaScript SDK - Users | JavaScript SDK | QuickBlox
React Native SDK - Users | React Native SDK | QuickBlox
Flutter SDK - Users | Flutter SDK | QuickBlox

Please be notified that resetting user password via email is available only for Enterprise plan.

Alternatively, you can use Update user option in order to implement reset password functionality in your applications:

iOS SDK - Users | iOS SDK | QuickBlox
Android SDK - Users | Android SDK | QuickBlox
JavaScript SDK - Users | JavaScript SDK | QuickBlox
React Native SDK - Users | React Native SDK | QuickBlox
Flutter SDK - Users | Flutter SDK | QuickBlox

Feel free to check our official documentation for more information that will help you to integrate QuickBlox services into your applications / projects or contact our Support team by submitting a ticket if you have any other questions.