Outlook is slow opening mailboxes or searching
MAPI-over-HTTP latency stacks up with a big mailbox cache and many folders. Cached mode gives local speed, online mode puts everything on the wire.
Try this first
- 1Enable Cached Exchange Mode and limit the sync window to 12 months
- 2Compact the OST via File, Account Settings, Data Files
- 3Disable add-ins you do not use, especially old CRM connectors
- 4Test with outlook.exe /safe to see if an add-in is the culprit
When to bring us in
For large shared mailboxes in cached mode: consider online mode or a separate profile.
See also
- My laptop is suddenly slowThree main suspects: a runaway background process, near-full disk, or a Windows update in progress.
- One specific application is slow for everyoneIf an app is slow for one person: local. For everyone at once: server side or vendor side.
- Opening files from the file server takes minutesOften the server itself is fine and the issue is network routing or stalling DNS resolution.
None of the above fits?
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