[MarkFL]

You can order the results by email...and it might not be a simple 1 or 2 step process, but it shouldn't be too bad.

Or, what you can do is run a manual SQL query to mass move all users having a particular email into a special usergroup you create for this purpose:

UPDATE user
SET usergroupid = X
WHERE email LIKE '%@spam.com%'

Replace X with the usergroupid of the usergroup you are going to move all the users, and replace @spam.com with the text common to all the emails in question.

After the query, all the spammers will be in the same usergroup, and you can prune them by that group.