macOS Outlook profile opens but cannot download shared mailbox

Scenario

A Mac user can open Outlook and their primary mailbox, but a delegated shared mailbox never loads correctly.

Recommended Resolution Path

1. Confirm the delegation works in Outlook on the web first.
2. Remove and re-add the shared account in Outlook for Mac after checking current app version.
3. Review whether the mailbox is too large or recently converted from another type.
4. Document whether the issue is isolated to Outlook for Mac or affects Apple Mail too.

Technician Notes

Document what changed, what confirmed the fix, and whether the issue points to a broader standards gap worth addressing for the client.