Dear Aaron Mackler,
Thanks for choosing Microsoft Community.
Based on your desrciption, I know the scenario you met. For this, please be kindly to try following steps to see if it helps:
- Open Outlook and go to File> Options> Advanced> Send/receive> click on the send/receive button, then click Edit.
- Find your account and un-check the option "Get folder unread count for subscribed folders"
- Under Received mail items, check the option "User the custom behavior defined below"
- In the window below that displays your IMAP folders just select inbox and leave the others unchecked
- Click ok and then exit out of options and perform a send/receive to test if there is any improvement.
Hope the suggestions above can help you. If there is any update, please feel free to let me know. Your understanding and co-operation are highly appreciated.
Thanks for your precious time. Have a nice day.
Sincerely,
Katherine