Expose IMAP capabilities for sharing folders, and delegating responsibility for an account (ex.: administrative assistant)

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https://groupoffice.readthedocs.io/en/latest/using/email.html#sharing-folders https://doc.dovecot.org/configuration_manual/shared_mailboxes/ https://docs.iredmail.org/mailbox.sharing.html

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Please use https://www.virtualmin.com/documentation/email/ as a reference implementation.