Can you override or customize email validation?

Yes, but only partially through FusionAuth's built-in features:

• You can customize validation using Customizations > Form Fields in the FusionAuth admin UI.
• However, if you want to completely implement your own validation logic, you would need to handle that within your own application and your own pages/API.

Resources

Here are some helpful links for managing user verification and email validation workflows:

• How User Verification Works
• Gate Accounts Until User Email Verified

If you need exact custom validation logic, you'll need to implement it on your application side and potentially use custom form fields to enforce it during registration or profile updates.