I received an e-mail from the mailbox manager

To help control the storage of our e-mail server we have installed a policy that will automatically delete old items from user mailboxes. Out of date items will be automatically deleted.
Calendar	Items older than 400 days
Deleted Items	Items older than 30 days
Inbox	Items older than 90 days
Journal	Items older than 365 days
Tasks	Items older than 90 days

Note #1:
This affects only the mailbox storage on the e-mail server. It does not affect the storage of e-mail programs.

Note #2:
Outlook programs set to access the exchange server (not POP3) are looking directly at the mail server storage.

Note #3:
This policy only affects the above folders. If you desire to save an item, create a new folder and store the items there.