Your Microsoft 365 backup has stopped seeing three places, and nobody changed the policy
On 1 October Microsoft started blocking EWS in Exchange Online. There are three locations with no Graph replacement you can back up with —public folders, the in-place archive and group mailboxes— and a process that is on by default and moves old mail into one of them at 96% of quota. Inside: what Microsoft says word for word, why the import and export APIs are not a backup, the deletion date set by your vendor rather than your retention policy, the inventory in six read-only commands, and the four questions to send in writing.
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