Outlook not automatically downloading new email

Copper Contributor

Hoping someone has seen this issue before and know what the fix is. I have one user who’s mailbox (in cached mode) is not automatically downloading new emails in desktop Outlook client.  On initial launch, Outlook’s Inbox will be up-to-date, but afterward does not automatically download new emails anymore – except if manually clicking on the ‘Update Folder’ button in Send/Receive ribbon.

I tried just about everything I can think of, but none of the following worked:

Clicking on the ‘Send/Receive All’ button doesn’t work.  (Only the ‘Update Folder’ button will trigger download of new emails.)

Creating new send/receive group

Create new profile, new OST, different cache length

Switching to a brand new PC. (Other user mailbox on the same PC works fine.)

Removing throttling policy doesn’t work.

Reducing mailbox size & item count doesn’t work. (Inbox has 220 items, Calendar has 1,573 items.)

Setting end dates on all recurring meetings.

Moving mailbox to a different Exchange server/database.

Toggling ‘Work Offline’ button.

Disabled ALL add-ins
Added regkeys from Outlook performance issues in a Cached Exchange Mode .ost or .pst file - Outlook | Microsoft Learn


Online mode works ok…but Outlook is slow in online mode. Mailbox is hosted on Exchange 2019 servers on Windows 2019 server.  Win 10 with Outlook 365 MSO v2202 64-bit.  Classic Hybrid and using Modern Auth for Outlook.  Since this is happing only with one user, I guess it’s something in his mailbox config.

I could delete and re-create the mailbox, but user has recurring online (Team/Zoom) meetings that we don’t want to cancel/re-schedule.

Anyone has other any ideas or suggestions to try? I have an open Microsoft support case for the past 2 months but issue persists.


1 Reply
Ran outlook.exe /cleanviews, /resetfolders, /resetreminders...also didn't help