Outlook stuck on Updating address book with Office 365

Ace-IT used Ask the Experts™

Outlook 2013 or 2016 connection to a standard Office 365 tenant are getting stuck on "Updating address book"
This happens on multiple PCs and all user accounts.
Online a basic tenant with 2 users and no ADSync or server etc.
This is stopping the rest of the folders syncing with the online mailbox.

I've done the following with no improvement:
Created the Outlook Profile on another Win 10 PC.
Created a new Office 365 mail enable user account and created a separate profile. Does the same for both users.
Downloaded the Offline address book in Outlook.
Renamed the OAB files.
Ran the Autodiscover test in Outlook.
Checked/ran the DNS test in The Office 365 Tenant.

Any help would be greatly appreciated.
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Blue Street TechLast Knight
Distinguished Expert 2018

Hi Ace-IT,

I'm assuming you set them up as MAPI accounts and not POP or IMAP - I have to ask only because I don't like assuming. Provided both accounts are setup as MAPI accounts are they in Online Mode or Cached Mode? Verify Send and Receive settings (Ctrl+Alt+S), click Edit. The account icon should have a red X and the Include the selected account in this group checkbox should be unchecked and everything grayed out (for standard Exchange sync). If you are syncing on a schedule, don't include the OAB. Have you called Microsoft about this yet (if not I would)?

Aside from the above; because of what you have already tried it leads me to believe it is environment-specific opposed to local, e.g. profile corruption, which is typically the case for OAB failure.

What is the make/model of your hardware firewall? Check the hardware firewall for DNS failures (public as well as MSFT related), outbound filtering or other mechanisms in the SecStack (e.g. App Control) that could be blocking traffic. Check the logs while you test. Also run a Packet Capture while testing.

Also, from within the network on one of the machines go here and test the account in the Office 365 tab: https://testconnectivity.microsoft.com/ Then post the results.

Make sure Windows OS and Office 365 are both updated too.

Let me know if you have any questions!


Hi Blue Street Tech,

Thanks for the reply.
Yes I've set them up as MAPI using Autodiscover and Online/Cached mode.
Sorry, I should have mentioned that I set both accounts up on my Win 10 PC in my Office (separate location,) so it shouldn't be environment specific.
I created new separate Outlook Profiles for each of the failing account to test as well.
Outlook works fine with my Office 365 account profile.

I've just ran the full range of tests in the MS Connectivity Analyzer with no obvious issues.
I also checked their results against the results from our working O365 domain to be certain.

Good idea with the MS Connectivity Analyzer as for some reason I didn't think of it, but unfortunately it's still an issue.
Last Knight
Distinguished Expert 2018
Did you find anything in the firewall logs?

Have you run a packet capture yet?

Have you tried changing the password on any of the problem accounts? If not do so and then create a completely clean install on a fresh Windows profile and fresh Outlook profile. I know it seems unrelated but make sure the OS and O365 are both current with updates.

If that test fails and you have setup everything correctly on the tenant, Outlook and you have duplicated this issue in other locations (other networks) using different machines. That would point to an issue server-side. I'd put a call into Microsoft to resolve.
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Distinguished Expert 2018

Have you tried contacting MS 365 support?


Thanks all,

Microsoft fixed the issue and it's now working properly.
I hadn't tried Microsoft Support before posting here as I didn't want to go though all the basic troubleshooting again if it was something simple.
After a few called and escalations, they sorted it out.
Blue Street TechLast Knight
Distinguished Expert 2018

Glad they got it taken care of... thanks for the points!

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