It is possible to bulk generate accounts with auto-generated emails. To do so, you need some email template in the correct format to be provided in the Email field of the Create Bulk Accounts screen:
Then, each account will be created with the email based on the specified template. The logic is similar to the logic used for username generation: some number will be added to the end of local-part. You can see the example email in the bottom-left part of the screen, next to the example username:
Email is optional for Bulk Account Creation, therefore a user might not specify any emails in the corresponding field and leave it empty. In this case, all generated accounts will have no email associated.
Note: We do not verify the existence or accessibility of email templates nor generated emails. We also do not attempt to create actual emails in any form. We do not enforce emails to be unique, therefore it is possible that two accounts may have the same email address associated. All these actions are out of scope for the system.