Source
r/sysadmin•
SysAtMN

Outlook Disconnected

Question

Hello,

​

I have a problem where users are getting stuck in Disconnected mode. The problem appears to happen at random while the users drive around their territory during the day.

A few observations:

  1. OWA works. The problem appears to be isolated to the Outlook client installed on the machine.
  2. Rebooting works. This is not an ideal solution as some users experience the problem several times a day.
  3. We use a Cisco VPN client.
  4. Outlook.exe /safe has no impact. The client opens and stays in disconnected mode whenever we use this feature. This suggests that the problem is not related to the add-ins.
  5. Outlook Connection Status tool shows an authentication error. However there is no more details on what is going on.
  6. When Outlook gets stuck in Disconnected mode, Skype for Business cannot sign in.
  7. The user is fully connected to the internet and VPN. Download speeds are acceptable or ideal in most cases. I can remote control to the users machine with no problems.
  8. Nukeing the users mail profile and OST files has no impact. We bump into the same authentication issues whenever we try to add those features back.
  9. Restarting Outlook has no impact.

​

Screenshot of error message in the Outlook Connection Status window:

https://imgur.com/a/ypy99IB

​

My observations so far suggest that the problem is something outside of the Outlook client. The only way I can impact that component is by rebooting the entire machine and starting over.

​

Is there anything else I could try other than opening a ticket with Microsoft to expose more debugging information?

Posted Aug 17, 2021, 6:10 PM UTC

730
SnowTech•

Try hardcoding your DNS so the VPN wont affect the DNS.

3
SysAtMNOPSysadmin•

Will do.

1
tjn182Sr. Sysadmin•

Are you on-prem, hybrid, or full cloud Exchange?

Had a similar experience with our hybrid setup.

​

HKLM\SOFTWARE\Policies\Microsoft\Windows\NetworkConnectivityStatusIndicator

REG_DWORD

Value Name: UseGlobalDNS

Value Data: 1

We have a group policy for this guy. We were constantly having issues with machines with "limited connectivity" and if I recall - it kept popping Outlook into Offline Mode.

Worth a shot.

Can also check and see if it recognizes that it's on a metered connection and is disabling Outlook to limit data.

3
SysAtMNOPSysadmin•

We have a hybrid deployment. Some in cloud but most are on-prem. I'll have to read up more on this regkey. I have not observed Outlook complaining about a metered connection in this scenario, but we have seen that error before. I believe most users who have the problem are on a built in cellular modem at the time. Windows occasionally classifies this connection as metered.

1
tjn182Sr. Sysadmin•

We had a similar setup - but we took down our on-prem and went "almost" full cloud. It still syncs from our AD up, and not-visa-versa.

We also have many sales running around with built-in cellular, so I feel your pain.

​

Another possibility:

Assuming your exchange is hosted behind the same firewall as the VPN - It is possible that it's remembering the off-the-vpn (external) address for the Exchange server. For example, it knows that it's 10.255.255.255 - which is the (fake) external IP of your Exchange. Yet you're on the VPN, which is also at 10.255.255.255 , it tries to go to 10.255.255.255 (Exchange, but also your currently connected VPN) and fails. A reset subsequently flushes the DNS, allowing it to reach out and resolve internally / externally properly.

1
Entegy•

Do you have a utility that messes with DNS like Cisco Umbrella?

2
SysAtMNOPSysadmin•

Not sure, I'll have to verify.

1
SysAtMNOPSysadmin•

No DNS utilities like Cisco Umbrella. We have a load balanced DNS server. I'll try to run an IPConfig /all on the next user to confirm if anything looks unusual in that area. I'll also try a few different ways of reconnecting the WiFi/Cellular adapter and VPN to see if that has any impact.

1
Unified_MicrowaveSysadmin•

I was going to ask this question about Cisco Umbrella. Many users at my organization had this issue with Outlook and Teams until I applied the GPO mentioned here: https://support.umbrella.com/hc/en-us/articles/230900948-Umbrella-Roaming-Client-Microsoft-Windows-Limited-Network-Connectivity-Warning-Yellow-Triangle-

I haven't heard anything about it since I applied it a couple of months ago. If you can reliably recreate the issue, I would try it on a test system.

1
SaltMonster1024•

I have seen that for a random set of users and intermittently for months; it is a DNS problem when the AnyConnect client is active.

Sometimes ipconfig /flushdns or sudo killall -HUP mDNSResponder (for Mac) fixes it, sometimes not. Sometimes, clicking off IPv6 on the wireless adapter fixes it (Windows).

Very frustrating.

2
SysAtMNOPSysadmin•

Will do.

1
SadLizard•

Does the network connection have globe and says 'no internet access' ?

Outlook is bound by that and doesn't care for anything if it says 'no internet access' even if there is.

Some steps: https://docs.microsoft.com/en-US/troubleshoot/windows-client/networking/internet-explorer-edge-open-connect-corporate-public-network

2
SysAtMNOPSysadmin•

We have had to deal with "no internet access" from the status indicator since the rollout of Win10. It was my understanding that this was due to our always on VPN policy. If this is the problem then I'm not sure we can do anything about it.

1
petrix•

We ran into this behavior when the user had skype for business or teams running in background. It seems that outlook and teams or skype for business use the same .ost. The solution was simple: close teams and restart outlook. After that, start teams again… hope this helps

1
SysAtMNOPSysadmin•

Will try this. Lots of good ideas that suggest it has something to do with dynamic DNS entries too.

1
RunningAtTheMouth•

I had a similar problem. Check credentials on credential manager. Remove any related to outlook or ecmxchange.

1
stampy4x4•

This! - I had tried everything to try and get a users outlook connected again. Was just in a constant state of disconnected. Connection Status had no entries in it, Test auto config returned correct results.

I could create a new profile and it would stay connected for a period of time. Sometimes days, sometimes weeks.

After much troubleshooting the thing that fixed it was removing a saved credential for a shared mailbox that this user had access too. As the user has delegated permissions it should be using her primary email to login to the shared mailbox anyway. and after removing the saved credential for the shared mailbox, outlook connected just fine!

2
SysAtMNOPSysadmin•

i had tried clearing the local credential manager of all cached credentials but no change. I think the theory on DNS is the most promising. Like if the user opens outlook offline, then connects to VPN, maybe Outlook or something is not updating to talk to the vpn connected resources so it just fails.

2
biosmatrix•

Check the exchange servers event logs for CAS related issues (Is CAS a thing anymore?). Whilst reviewing a customers exchange env. once to get to the bottom of some MAPI issues, I saw CAS event errors - it was being hammered and throttling kicked in.

Also if a load balancer is in use bypass it for a few users facing the issue and see if it’s the cause (Use hosts file to bypass).

1
SysAtMNOPSysadmin•

good suggestions. Ill try this out.

1
biosmatrix•

Don’t keep us all guessing…. Come back and let us know how you solve it!

1
SysAtMNOPSysadmin•

will do. however, its not easily recreatable and the users are very mobile. its hard to nail down a time where we are all available to troubleshoot this one.

might be a while before i can post any updates. if so then ill probally start a 2nd post and refer back to this one.

2
biosmatrix•

Roger that. Also don’t forget about Outlooks troubleshooting logs!

1
p-zelaskoWindows Admin•

Roll out a VM or VDI, have them log in and open outlook. Worth it to see what happens. Would rule out a local issue of any sort!

1
SysAtMNOPSysadmin•

im convinced its a local issue. Outlook Web Access works correctly on the same machine when the Full outlook client is stuck in disconnected mode. Pretty sure if i hand the user a 2nd machine it would work.

But then again a vm wouldnt have changing network conditions so it may never reproduce the problem. i only have the issue with vpn connected users at the moment.

1
p-zelaskoWindows Admin•

Right, OWA is a direct display of what's on the server, outlook desktop app most of the time uses cached mode which can get corrupted for multitude of reasons. Clearing the outlook profile and entering outlook safe mode are all great troubleshooting steps, but they don't account for the entire machine that the outlook app is located on.

If you don't have a separate machine available immediately it's worth running Microsofts Sara tool to try to pinpoint what's wrong.

1
SysAtMNOPSysadmin•

ill look into the MS Sara tool. thats a new one for me.

1
p-zelaskoWindows Admin•

It's actually pretty intuitive. Not an end all be all, but nothing really is with computers is it.

1
No-Neighborhood2338•

I'm having the same issue since last week. Only a few machines are doing it. I suspected it was a device limit thing, nope

1