Outlook cannot log on. Verify you are connected to the network.

I’ve seen this great little error occur with Microsoft Outlook 2016. It’s so great that even completely uninstalling Office 365 ProPlus and reinstalling it doesn’t get rid of the error. This is on Windows 10 with the latest operating system updates applied.

“Outlook cannot log on. Verify you are connected to the network and are using the proper server and mailbox name. The Microsoft Exchange information service in your profile is missing required information. Modify your profile to ensure that you are using the correct Microsoft Exchange information service.”

Click OK and you get:
“System resources are critically low. Close some windows.”

“Cannot start Microsoft Outlook. Cannot open the Outlook window. The set of folders cannot be opened. The information store could not be opened.”

It’s an indication that your Outlook profile is corrupted.

If you try to fix it by uninstalling Office 365 ProPlus and reinstalling it again (which uninstalls Outlook), those profile settings remain and you still get the error.

The solution:
Remove and re-create your Outlook profile, under Control Panel – Mail – Profiles

NB: This WILL delete your .ost offline storage file and re-sync your entire mailbox.
But it will also fix the error and you won’t need to reinstall Office.

After going through several recurrences of this problem, I haven’t had it again for a while. My theory is either it was a bug in one of the builds of Outlook or it had something to do with Outlook being open while my Windows 10 device goes into sleep mode and then re-wakes. I’ve started shutting my machine down completely every night instead of sleeping it.

The next tricky part is when the creation of your new Outlook profile fails.

You get an old school style Internet mail popup box saying “Enter your user name and password for the following server” with the server populated with your domain name. No possible combination of your actual correct password will work.

Your next fix involves a registry key.

Outlook is doing a lookup on the root record of your https domain to try and autodiscover your mail server. It’s not finding the Office 365 server it needs, because the Office 365 server is in a completely different place than your company website.

You need to locate the registry key:
HKEY_CURRENT_USER\Software\Microsoft\Office\x.0\Outlook\AutoDiscover (where x.0 corresponds to your version of Outlook, from 12.0 for 2007 through to 16.0 or Outlook 2016).
Here you need to add a DWORD value called ExcludeHttpsRootDomain and set it to 1

Add the same DWORD value under: HKEY_CURRENT_USER\Software\Policies\Microsoft\Office\x.0\Outlook\AutoDiscover too.

Now Outlook should connect to Office 365. If it doesn’t, check this support article for some more DWORD values to try.


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