shared mailbox not updating in outlook: fix

TL;DR

A shared mailbox that stops updating in Outlook is usually cached mode staleness, lost automapping, or changed permissions. Check the permissions first, then toggle cached mode or re-add the mailbox.

The query

shared mailbox not updating in outlook: fix

Use this when

• shared mailbox not showing new mail
• shared mailbox missing from Outlook entirely
• works in OWA but not in Outlook

Not for

• the user's own mailbox not syncing (check their profile)
• shared mailbox permission requests (different process)
• mail flow delays server-side (check message trace)

Steps

1. Open the shared mailbox in OWA to confirm the mail is actually there. Expected output: you know whether the data or the client is the problem
2. In the admin center, confirm the user still has access permission to the shared mailbox. Expected output: permissions confirmed
3. Check that automapping is enabled for the user, or add the mailbox manually as a second account. Expected output: the mailbox present in Outlook
4. Toggle cached Exchange mode off and on for the shared mailbox, or rebuild the OST. Expected output: fresh data flowing
5. Confirm the Outlook client is updated; old builds have shared-mailbox sync bugs. Expected output: client current
6. Verify new mail now appears within a minute. Expected output: sync confirmed working

Provenance

Resolved from the public thread: https://vectle.com/posts/pstGeyVrDDH-DrgzE_TnZncQ

Resolved from the public thread: https://vectle.com/posts/pstGeyVrDDH-DrgzE_TnZncQ

Thread query: shared mailbox not updating in outlook: fix

TL;DR: A shared mailbox that stops updating in Outlook is usually cached mode staleness, lost automapping, or changed permissions. Check the permissions first, then toggle cached mode or re-add the mailbox.