All my emails disappeared for over 20 years.

To recover your missing emails from 2025, you can follow these steps:

1. Check the Deleted Items Folder: Since you found approximately 40,000 emails in the Deleted Items folder, start by reviewing this folder. You may be able to recover some of the emails from there.
2. Recover Deleted Items: If the emails are not in the Deleted Items folder, you can use the "Recover Deleted Items" feature. This feature allows you to restore items that have been permanently deleted from the Deleted Items folder, provided that the retention period has not expired. To do this:
   • In Outlook, go to the Deleted Items folder.
   • Look for an option like "Recover Deleted Items" or "Recover Deleted Items from Server" in the ribbon.
   • Select the emails you want to recover and restore them to your mailbox.
3. In-Place eDiscovery: If you are unable to find your emails using the above methods, and if you have administrative access, you can perform an In-Place eDiscovery search to look for missing items in the mailbox. This can help locate emails that may have been moved to the Recoverable Items folder. You would need to use the Exchange admin center or PowerShell commands to perform this search.
4. Contact IT Support: If you are still unable to recover your emails, consider reaching out to your IT support team or email administrator. They may have additional tools or permissions to assist in recovering lost emails.

Make sure to act quickly, as the ability to recover deleted emails may depend on your organization's retention policies and the time elapsed since deletion.

References:

• Recover deleted messages in a user's mailbox in Exchange Online
• Recover deleted messages in a mailbox in Exchange 2013