It's incredibly slow, at least a minute to load the next message after deleting. This is going to take me months to delete the "conversations" that would not have been in my inbox previously. I would assume that all members who have messaged other members and gotten no reply will have all those end up in their inbox as well.
When logging in to a normal user test account which has only a few messages in it, the plugin performs quite well. So I think it's safe to assume that the slow performance is due to massively overloaded inboxes now that the new plugin has made "conversations" out of every sent message a member has made.
PLEASE update this plugin with a "purge inbox" or some sort of bulk delete feature.
