Microsoft have made some recent changes to the latest Outlook builds, especially in Outlook 2016 onwards, and these changes are causing some users problems with normal Outlook connectivity under certain circumstances.
This guide will help you deal with the issue and restore connectivity to your mailbox on our system.
Firstly, close Outlook.
Now download the following file, save it to your Desktop, then double-click it and select OK when asked if you want to add entries to your Windows registry.
Disable Outlook 2016 Autodiscovery looking to Office 365 and/or Outlook.com (right mouse click then "Save link as..." to save the .reg file)
Now open a Windows Command Prompt, type the following, then press Enter:
ipconfig /flushdns
Now reboot your PC
After your PC has rebooted, navigate to the followng location:
C:\Users\<your_user>\AppData\Local\Microsoft\Outlook
Delete any files that end with -autodiscover.xml
Still in that folder, delete any files ending in .ost
Stay with us; you're almost there.
Now navigate to the following location on your PC:
Start > Control Panel > Credential Manager > Windows Credentials
Delete any credentials you find that relate to Outlook, Exchange and/or Office 365.
While still in Control Panel, navigate to Mail (Microsoft Outlook 2016) (32-bit)
Finally, delete your old mail profile and create a new one. This should now complete successfully.
Once you're satisfied it has, you can now restart Outlook where you will again be asked to enter your credentials. Be sure to tick to save them. Outlook should now open and function normally. However, if you're still experiencing issues, be sure to open a support request for more assistance.
