All my outlook 2019 suddenly disconnect from ovh exchange server

Guillaume SPECQUE 0 Reputation points

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:

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.

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Outlook Management
Outlook Management
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  1. Yuki Sun-MSFT 40,781 Reputation points

    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:

    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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  2. Guillaume SPECQUE 0 Reputation points

    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!!!