> You're assuming the new hire will be able to process all information and - if I'm reading your comment correctly - read all messages and / or e-mails sent to

> You're assuming the new hire will be able to process all information and - if I'm reading your comment correctly - read all messages and / or e-mails sent to everyone. No, just that they'll search for whatever information they need to do their jobs within the company's archived email. The nice thing about email is that each message is dated and comes with the author and the author's contact info, so you know exactly who to ask if they're still at the company. (And if they're not at the company, you can ask if you're allowed to contact them depending on the context, or at least figure out who they worked with.)