A feature that I would like is a two-level view of the email blacklist so to group email addresses of the same email domain. Thus the top level would be a list of the email domains. Top level entries would have a group of regular email addresses, being the second level view, that belong to that email domain.

It would have the benefits of:
- Blacklists would be easier to view as groups of email addresses could be collapsed and expanded on demand.
- Some user features that operate on a group of email addresses would be easier to implement.

An example of a group operation would be the replacing all emails of the same email domain with a single regular expression. (utahjeff [url=/posts2730-90.html][/url])

I do think this idea needs some thinking though. Restricting the view to two levels would make for simplicity but would not handle issues such as:
1. '*@spam.com' and '*@*.spam.com'.
2. '*@spam.com' and '*@spam.*'. Could be multi-levels of groups but what would be the rules to automatically assign to the right level?

A two-level view should work well enough.