some sent emails are missing and moving to "recover deleted items"

spring8080 

Sorry for the inconvenience or delays this issue may have caused you. Just like you have mentioned that emails from the sent items folder are moved into the recoverable items folder for users in your organization.

To start troubleshooting, could you please let me know when the issue started? Was there any recent changes that you are aware of? Is the issue reproducible when logged into the web version of outlook? Are they logged into the updated version of Outlook? Do they make use of Outlook on their mobile devices?

There could be a chance that a rule has been mistakenly setup on their app devices, hence causing the automatic deletion. Can they remove their account permanently oh their mobile devices and observe if the issue will be reproduced? How often does this happen? Does it occur with new set of emails, emails from particular domain or all emails (both internal and external organization)? Do we have working users? What is the difference between the working users and the non working users?

Let us also confirm if there is a rule triggering the effect of the email disappearance. This can be confirmed from the user end and also from the exchange admin console too. Does the issue occur when logged in to another machine of a working user?

Please feel free to respond at your earliest time to continue to work with you. Thank you!