theymos has said that he is willing to prune your messages for you and provide you with a file containing all your (pruned) messages that is compatible with most email software (but that he will only do this once per user).
I am not sure if this will be resolved with the new forum.
You can somewhat resolve the issue by having PM notifications be sent to you via email, just be sure that you don't take any action on any PM you look at via email because it will be much more difficult to check for imposters and to parse what was quoted and what was said by the sender.
Thread locked.