[markbolyard]

Through your admincp, in the Maintenance area, select execute sql querry.

Use this:

UPDATE vb_user
SET usergroupid = 149
WHERE email LIKE '%@mail.ru%'

You will change vb_user to just user if you are now using prefixes in your database.

You will change the usergroup number to a usergroup which you can use temporarily to store those members you want to delete. So, you could make a new usergroup like I did and call it To Be Deleted, or Bad Email Accounts, and place that usergroup number in the code above.

Then change the @mail.ru to whatever email you want to move to that bad email usergroup.

Once you have all your users in one usergroup, then you can prune those users under the user menu by usergroup.

Hope that makes sense, and although not the easiest method, that's all I got