Hi @AAdams876 ,
Did you enable the AutoArchive setting below?
If so, according to the Setting Description, it is normal that the AutoArchive setting in your Outlook desktop would greyed out. I also did the same tests in my Outlook, when we checked the "Delete expired items" or "Permanently delete old items" in the AutoArchive setting of GPO, all the AutoArchive settings in Outlook desktop client will grey out.
And if we checked the “Archive or delete old items” option, you will see the AutoArchive settings in Outlook desktop like below:
Usually each Outlook folder has its own Archive setting, if you would like to apply AutoArchive setting to all the folders, you can try the "Apply these settings to all folders now" option.
As I know, there might be several factors which could cause Outlook AutoArchive feature not work, for example, wrong settings, damaged archive.pst and others.
In order to conduct further researches on your issue, it is suggested for you to check your AutoArchive settings again. After the configuration, you could manually run the AutoArchive feature from the Outlook desktop client(File > Mailbox Settings > Clean up old items > Archive all the folders according to their AutoArchive settings > OK) for the first time, so that we can make sure the Archive location and datafile is fine. And then, you could check if this feature could work normally in the next operating cycle.
Hope this can be helpful.
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