Password reset without sending passwords via email?

I need to move more than 20.000 users from a typo3 driven website to a Joomla/CB website. User profile migration is not a problem, but the passwords are.
Since the passwords on the typo3 site are of course encrypted, there is no way to transfer them to the new server. I would inform my users that they'll have to reset their passwords at their next login, but in Europe with GDPR being active, I don't think it would even be legal, to send a password that should protect personal data in plaintext via email.

Plain text passwords sent in emails only happens for generated password as there is no other means of sending their password. Once you've imported your users you should be able to use the batch tool in Users > Manage to set "Require Password Reset" to "Yes". This has to be done from Joomla user management at this time since we don't have that batch option in CB > User Management yet.

I see, so I import the users and at their first login they use the 'forgot password function' to get a new temporary password, that has to be changed at their first login?
Regards
Markus

I guess your best option is to set their passwords to random passwords. If using CB > User Management import feature you can do that by just leaving password out of your import. They'd then have to use forgot login to get a new temporary password, which of course will be emailed to them as again there's no other way to give them a password that was generated randomly. Eventually forgot login will be replaced to no longer need that, but for now that's how it works.