All my outlook 2019 suddenly disconnect from ovh exchange server

Question

Hello all!

Something crazy is happening to me.

Yesterday, from 4:00 p.m. onwards, all the outlooks of my 50 machines suddenly lost connectivity to the exchange server hosted at OVH.

At first I was not unduly worried since it happens sometimes but the service is restored after 30 minutes max. The symptom was as usual... ie a loss of connection to the server with the outlook login and password prompt.

Except that now it has been going on for 20 hours.

No matter how hard I search, I can't find it. I reinstalled a very clean machine free of firewall or antivirus, on a different network in vain... the latest win10 and outlook updates are done.

I deleted the credentials that concern Outlook and office in general in the conf/account management panel...

I also did a connectivity test here: https://testconnectivity.microsoft.com/tests/O365EwsTask/input

the latter generally passes but still emitted errors concerning encryption. I put them below.

Honestly I don't understand, it's as if all the passwords suddenly changed. However, I did a password change test on OVH but in vain.

Crazy thing again: I connect without problem to webmail and on mobiles! The problem is focused on Outlook.

And last point even more phew: none of my w10 connects to the OVH exchange, however the only two W11 connect without problem and have never suffered this cut.

I leave it to you friends, because here I am completely dry. For me there is a report with an SSL problem, certificate or other...

Tell me

Thanks for reading me ;)

PS: obviously OVH sees no problem on its side and is reactive like a mussel on a rock.

Answer 1

Hi @Guillaume SPECQUE ,

Welcome to Microsoft Q&A!

Since I know little about OVH, I'd like to confirm which version of Exchange server you are using? Noticed that you selected "Office 365 service" when running the test using Microsoft Remote Connectivity Analyzer, so is it that your email accounts are hosted in Exchange Online?

Besides, please run an Outlook connectivity test using the following link instead and see if any clues can be found:

https://testconnectivity.microsoft.com/tests/O365Ola/input

It's also suggested to use the Test E-Mail Autoconfiguration service in Outlook and check the output:

1. While Outlook is running, click the CTRL key and then right-click the Outlook icon in the system tray, select “Test Email Autoconfiguration”.
2. Confirm that your email address is in the address field, uncheck “Use Guessmart” and “secure Guessmart authentication” boxes. Then click the “Test” button.
3. Once it runs, check the Log tab and Results tab.

Furthermore, I can understand that you may have already verified that there's no problem on OVH side, but considering that the issue is indeed involving OVH, personally I'd still suggest trying to visit the OVH community as well to see if there are others who are in the same situation or have experienced similar issue.

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Answer 2

hi again,

I did a test, i installed outlook and configured it on a personnal PC and it works.

My corporate pcs lost connexion and it still down sinc 5 days long.

I think there was a security update on OVH private exchange which broke connexion, and even if re install outlook on my coroprate pcs it doesnt work.

It is not the network because outlook dont work on my corporate pcs on corportae network and personal network.

Only both W11 can connect and work...

it s mad mad mad!!!! it's driving me crazy!!!

Answer 3

Having struggled with this issue for a while now, this could be related to using a Work or School account with Windows (Windows 10 Pro in my case), which ties a ton of stuff to your Microsoft Account through Entra. I am very much convinced that despite Autodiscover being properly setup, Outlook persists in trying to login with Entra or Exchange Online when it really shouldn't have to. And of course the email account doesn't exist over there since it's hosted on OVH. I know there are several people with this issue and still haven't been able to find a solution.

In my case, running the tests at https://testconnectivity.microsoft.com/tests/Ola/input is successful (apart from warnings regarding the fact the SSL certificate is for ex2.ovh.mail.net instead of our company domain name, which is normal and not a problem), there is literally no reason Outlook (from my company's Office 365 subscription) can't add the Exchange account from OVH, and it works on all of my colleagues' PCs (though a lot of them are either running on Mac, Windows 11, or Home editions of Windows 10), but not on mine. I can set up my email using Outlook on my phone, with no issues.

I can also configure the emails (minus calendars and shared contacts which is critical in my case) as IMAP accounts, but they used to work as Exchange with no issues whatsoever and suddenly stopped all at once and now stick me in a credential loop forever. I cannot have a single Exchange account in my Outlook or it'll get stuck in that loop. I have tried everything in registry, clearing credentials from credentials manager and so on.

OVH says it's not their problem, that it's an issue with Outlook that they don't provide assistance for setting up email clients, and send me to Microsoft for assistance.

Microsoft says it's not their problem as the Exchange Server is hosted by OVH and see with them.

Our company's Microsoft business account tech support say they only deal with issues related to Office 365 (Microsoft hosted emails) and can't help with Exchange Server.

Basically everyone tries to offload the problem to someone else and clean their hands of it. I'm sick of this.

The best alternative I've been able to find is to use Thunderbird with TbSync extension and EAS-4-TbSync provider extension. This allows you to setup your email as IMAP and use the extensions to sync calendars and contact lists using Exchange ActiveSync protocol. Together, these provide the full range of features Outlook provides, but without Microsoft's dumb credentials bug no one will acknoledge and fix.

TLDR: It's a problem with Outlook but Microsoft doesn't care about a minority of users who aren't using Exchange Online on Microsoft 365, so just stop using Outlook. They're never going to fix this.