Most Microsoft 365 tenants will have to manage the mailboxes of ex-employees. Retention policies are an excellent method to achieve this goal, if you remember to add mailboxes to a suitable retention policy before deleting their Azure AD account. In this article, we consider Microsoft’s recommendation to use a specific retention policy for inactive mailboxes and how to go about using such a policy.
https://office365itpros.com/2021/10/19/use-microsoft-365-retention-policy-manage-inactive-mailbox-co...
