Hi @John Moscato ,
As regards to the AutoArchive tab, are you talking about the image below in the Outlook for Windows?
If it's true, this is used to exclude this folder from the autoachive settings. But as far as I know, auto archive is currently only available in Outlook for Windows, while you are using Outlook for Mac, right?
Do you mean this has been worked for you previously on the same email account? Was it on Outlook for Mac with New Outlook toggled off? Feel free to let me know if I have misunderstood anything.
With the above being said, based on my knowledge, messages may also be automatically deleted because of the retention settings configured on the server level. If this is the case, for default folders like Inbox, you may need to contact your administrator to modify the retention setting, and for personal folders, you can right click on the folder to see if you can manually adjust the retention tag:
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