Many popular emails such as Microsoft Outlook will delete all your emails from over a year ago, and also delete your email address.

So be careful linking your exchange account to one of those email accounts. Make sure you check your email regularly so they do not delete your account.

For example, I had many important legal documents in that email address of Microsoft from a few years ago, and they deleted all of them.
Also, I can't remember if I invested in Bitcoin many years ago, I guess I will never know because they deleted all my old emails.

Great to know.