daknetworks.com

Open Outlook 365. The Windows Security Box shows. You type in the password. The box shows again. And again. And again. What gives?

 This could happen for a few reasons.

1- check the DNS records. There should be an autodiscover on the company domain name. In other words: autodiscover.daknetworks.com should go somewhere. And that somewhere should be correct.

2- check the DNS records. If there is more than 1 domain, then the autodiscover needs to be on all of the domains. In other words, autodiscover.daknetworks.net should go somewhere as well. That somewhere should be the same somewhere as the main domain.

3- check the Control-Panel > Credential Manager. Close Outlook. Delete any username/password that indicates Outlook. If there are incorrect username & password saved in there, they will be used to access the email. Since the username/password are incorrect, it will ask for the correct username/password.

4- check the registry at:
HKEY_CURRENT_USER\SOFTWARE\Microsoft\Office\16.0\Outlook\AutoDiscover\

There are 2 parts to Outlook. The client software, what you are using on your system, and the server software, what the entire company is using to store/send/receive email.

Beginning with Outlook 2016/Outlook 365 some of the options to manually set what happens are removed in an effort to try to make setup easier.

If you have Outlook 365, then most likely you have Microsoft 365 for the company and it tries to automatically connect to the Microsoft 365 server.

But if you have Outlook 365 and have a private Exchange server, that can cause a mismatch. This results in Outlook always asking for a username/password for the Microsoft 365 server.

Outlook 365 automatically goes through a list to get autodiscover information. This is as follows:

- PreferLocalXML
- Office 365 | ExcludeExplicitO365Endpoint
- Root domain look up (Fancy way of saying it queries the A record) | ExcludeHttpsRootDomain
- Secure URL look up | ExcludeHttpsAutoDiscoverDomain
- Local Autodiscover (SCP object) | ExcludeScpLookup
- HTTP redirect | ExcludeHttpRedirect
- SRV record look up | ExcludeSrvRecord
- Last Known URL | ExcludeLastKnownGoodURL

To skip a method, this is set via a registry edit. All items below skip/exclude the method of finding the AutoDiscover settings except the PerferLocalXML setting which dictates that a local override is to be used:

reg add HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Outlook\AutoDiscover /t REG_DWORD /v PerferLocalXML /d 1
reg add HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Outlook\AutoDiscover /t REG_SZ /v domain-name-here.tld /d 'C:\path\to\autoDiscover-domain-name-here.tld.xml'

reg add HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Outlook\AutoDiscover /t REG_DWORD /v ExcludeHttpRedirect /d 0

reg add HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Outlook\AutoDiscover /t REG_DWORD /v ExcludeHttpsAutoDiscoverDomain /d 1

reg add HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Outlook\AutoDiscover /t REG_DWORD /v ExcludeHttpsRootDomain /d 1

reg add HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Outlook\AutoDiscover /t REG_DWORD /v ExcludeScpLookup /d 1

reg add HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Outlook\AutoDiscover /t REG_DWORD /v ExcludeSrvRecord /d 1

reg add HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Outlook\AutoDiscover /t REG_DWORD /v ExcludeLastKnownGoodURL /d 1

reg add HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Outlook\AutoDiscover /t REG_DWORD /v ExcludeExplicitO365Endpoint /d 1

5- trial software. There might be Office trial software installed along side of the Office software:

• -Open COMMAND-PROMPT (as admin)
• -Check the license, type:
  C:\Program Files (x86)\Microsoft Office\Office16\cscript ospp.vbs /dstatus
• -Uninstall the license, type:
  cscript ospp.vbs /unpkey:[productkey]
  (ie: cscript ospp.vbs /unpkey:VMFTK)
• -Restart the system.

NOTES:
-https://docs.microsoft.com/en-us/outlook/troubleshoot/domain-management/unexpected-autodiscover-behavior
-https://support.microsoft.com/en-us/help/3211279/outlook-2016-implementation-of-autodiscover
-https://docs.microsoft.com/en-us/Exchange/architecture/client-access/autodiscover?redirectedfrom=MSDN&view=exchserver-2019
-https://practical365.com/exchange-server/fixing-autodiscover-root-domain-lookup-issues-mobile-devices/