May I know is any command to permanentyly delete a folder in Vault in EV server? Since I have a user who has 30K email in this folder and he doesn't do it in Outlook.
You can delete any folder just by right-clicking it in EV Search and choosing Delete.
However, it must be empty (no items and no subfolders) for the deletion to succeed.
There is not (as far as I know) any override command that allows you to delete a folder that still has items in it.