- Set `auth.email-domains` to `@company.com`.
- Registered with `aaa...aaa@evil.com@company.com`. Previously this worked, now it is rejected.
- Did a valid registration.
- Tried to add `aaa...aaaa@evil.com@company.com` as an email address. Previously this worked, now it is rejected.
- Did a valid email add.
- Added and executed unit tests.