Blacklist and Auto-approve list
As an added layer of security, Administrators of private IdeaScale communities can use email-based access control to specify which domains have permission to register with the service. This tool works when members are added, but it does not work retroactively.
Administrators can configure the Email-based Access Restrictions Control Panel from the Security settings tab on the dashboard.

All email domains will fall into one of two categories, Blacklist (rejected) or Auto-approve list (approved). If there is no entry in "Auto-approve list" the domain will always be allowed.
Blacklist
Add any email domains you wish to reject to the Blacklist.

Auto-approve list
Email domains matching this list will be auto-approved.
You can select which action will be performed when an e-mail domain does not match Auto-approve list.
- If "Moderate Access" is selected, the request will be sent to a moderator. In this case, whatever might be the community setting, moderator will be sent an email for moderation and membership will be pending until moderated.
- If "Reject Access" is selected, the domain will be automatically rejected.
- If "Approve Access" is selected, then the domain will be automatically approved. In this case, if community setting is to moderate then the email will be moderated, otherwise approved
If there is not a Auto-approve list entry, the email domain will be approved. The entry can take 3 forms:
- domain.com
In this case, domain and subdomains will be checked. - @domain.com
In this case, the domain will be checked but no subdomains. - user@domain.com
In this case, the exact email address will be checked.