Comments on: Unexpected Authentication Prompts in Outlook

By: Geoff E

Geoff E — Mon, 12 Oct 2020 20:13:47 +0000

In reply to Jackie. Yes, my company is experiencing this issue. Office 2016, Exchange 2016 CU17.

By: Jackie

Jackie — Sat, 03 Oct 2020 18:43:45 +0000

Are others still experiencing this issue? We use Outlook 2016 and Exchange 2019 CU6.

By: Ivy

Ivy — Wed, 17 Jun 2020 12:02:16 +0000

Hi Rico, i know it’s a really long shot . But how did you manage to fix your issue?
We are currently having that exact same issue right now, and can’t find any solutions.

Regards,

By: Phil

Phil — Fri, 08 Mar 2019 03:45:05 +0000

Hi Paul
We have this issue with our new Hybrid. It affects all on-premise users who connect to O365 shared box or calendar. Looking at your comments around namespaces, should autodiscover be pointing to the 2016 Hybrid Exchange Server, or the existing 2013 Exchange Server i.e. mail.domain.com, or hybrid.domain.com?

By: Udeme Ibanga

Udeme Ibanga — Thu, 23 Nov 2017 04:53:38 +0000

Just a quick update on this issue, disabled mapi over http and all is now well for almost a week now. We have been able to migrate more mailboxes and no user complaints again on the password prompts. I will revisit enabling the new protocol when we move our clients from Win7/Outlook2010 to Win10/Outlook2016.

Many thanks Paul, your website is a priceless for knowledge.

By: Daniel

Daniel — Tue, 21 Nov 2017 09:11:25 +0000

In reply to Eugene Beran. I found at least a workaround: I have to admit I have never paid much attention to autodiscover because it was working years without. We do not have DNS records for autodiscover.domain.com. We have a SRV record internally but that's it. I now figured out that when I add an entry for autodiscover.domain.com to the local hosts file on the clients the password prompts just disappear. They receive a certificate warning at the moment because the entry in the hosts file points to the owa.domain.com IP address but when they confirm the certificate the password prompt is gone until they start Outlook next time when the will be prompted once for their password, but not every few minutes anymore. I hope this helps someone.

By: Udeme Ibanga

Udeme Ibanga — Fri, 17 Nov 2017 22:44:43 +0000

Well, this took me weeks before I stumbled across this page. We have exchange 2010 and just introduced exchange 2016. The password prompts have been just over the place from inside to outside and has really hampered the project and user service perception.

I think I will investigate disabling Mapi over http for now till we upgrade our clients from outlook 2010 to 2016 in the near future.

By: Daniel

Daniel — Tue, 07 Nov 2017 16:06:45 +0000

In reply to Eugene Beran.

Hi Eugene,

do you have any resolution for this?

I experience the exact same problem. I have a few users who are only working remotely. If they have established a VPN connection everything is fine. If they don’t, i. e. if they access their mailbox directly through the internet, they get a password prompt every now and then. No matter what they put in, the prompt will reappear after some time (can be minutes, can be hours). Interestingly if they just click cancel at the prompt Outlook says “Need password” and if they afterwards click on the “Need password” Outlook status goes back to connected without providing any password. I have already pulled my hair out to resolve this but cannot get a clue why this is happening. I am pretty sure all of the users having the problem are running Outlook 2016 on Windows 10. Our Exchange is also 2016.

If anyone can help I’ll spend a German Weissbier! (Sorry, has to be picked up in Germany:-))

Daniel

By: Eugene Beran

Eugene Beran — Sat, 28 Oct 2017 19:46:26 +0000

I think this problem is not fixed. I had this problem on Exchange 2013 CU16 and spent hours testing it at night with my account running on fully patched Outlook 2016.
Now that I am on Exchange 2016, I’m trying it again and inside the office it seems fine, but once I put my computer on an external network, it wants a password. If I don’t put one in and hit cancel, email works just fine, but after a bit it asks for a password again.

On your hybrid page here: https://www.practical365.com/exchange-server/testing-new-exchange-hybrid-configuration-office-365/
You mention:
Note that the user will need to provide their credentials to authenticate to Exchange Online. Thanks to password synchronization they can use the same email address (which should match their UPN) and password as they use on-premises, and save the credentials to avoid being prompted every time

Seems to me that this password prompt is due to EO using Mapi as well. And having the user save it just means that maybe they won’t see it again until their password changes.

That would probably work in a local environment.
I’ve seen many posts in forums about people just giving up and letting their users put them in and save them or going back to RPC. I’ve seen many posts claiming tickets were opened up with Microsoft to no resolution.

By: Antonio

Antonio — Mon, 28 Aug 2017 22:18:48 +0000

In reply to Allen Boutwell. Hi Allen, Any updates on this from Microsoft, did you end up resolving your issue?