Soft deletions
Domino mailboxes have a default setting of 48 hours before soft-deleted emails are purged from the Trash. Some users at the firm I work at have realised that this setting is editable for the mailbox owner, and have naturally extended it. I think the most egregious extension I've seen was up to about 11,000 years (they put all the 9s in). Shame that soft-deleted items don't get carried over when you move a mailbox to a different cluster.... mwuhahahah