I am working toward closing a small business acquisition and came across an unexpected issue - the main owner and key employee has used their office email as personal email for a couple of decades and is not willing to give me access to their historical email at the time of closing because they have all their personal things in the email account. This person owns all the client relationships and corresponds with all the clients on a regular basis.

I would appreciate any suggestions on how to work through this issue!
Thank you.