locked
Outlook 2016 Pro Plus Digital Signature issue RRS feed

  • Question

  • Hi everyone, in my organization there are 50 clients, circa (Windows 10). On 8-10 of these, there's a single mail account configured with IMAP in Outlook 2016. From 15/10/2018 some emails from inbox automatically keep being sent in Junk Mail without any logical reason. The message shows an error window that tells me that the digital signature is not valid because the message content could have been modified or tampered since it has been sent.

    First I thought it was a certificate error, but the certificate is totally valid and expires in 2020. The problem is with the digital signature, but I really don't know what to do. I tried to launch all the Outlook clients in safe mode, but nothing changes. On the web interface of the mail provider, the "junk mails" are correctly displayable (although in junk folder) with the digital signature valid. 

    Please help me, I really don't know what to do, I'm going crazy. Thanks a lot.

    • Moved by Perry-Pan Friday, November 30, 2018 2:57 AM
    Thursday, November 29, 2018 11:45 AM

Answers

  • DECEMBER 12TH UPDATE:

    About one week ago I've proceeded with the first of your suggestions, that is to put the address of the digital signature to Safe List in Junk Mail options. It seems to be working, for now. Not a single mail in Junk (these days about 50 mail arrived safely) from December 5th.

    I can consider the problem solved, for now. I still don't understand the reason behind the sudden issue. Since I've modified the settings on the clients one by one, maybe one of them was problematic and I didn't notice. 

    Thanks to everybody for the help!

    • Proposed as answer by Perry-Pan Monday, December 10, 2018 8:44 AM
    • Marked as answer by Miyamoto_89 Monday, December 10, 2018 8:50 AM
    Monday, December 10, 2018 8:39 AM

All replies

  • Hi Miyamoto_89,

    Does it happen to specific senders? What if we add them to Safe List in Junk Email Options?

    We can double click the signature line or the red Signatures button in Outlook and then click Details to check more information about the certificate.

    We can try repairing Office to see if it helps. To do this, please go to Control Pane > Programs and Features. Right click your Office suit and then choose Change. Click Repair.

    If issue persists, we can also create a new profile in case personal settings are corrupted. Please refer to the steps in this link.

    Any updates, please feel free to tell us.

    Regards,

    Perry

    Please remember to mark the replies as answers if they helped. If you have feedback for TechNet Subscriber Support, contact tnsf@microsoft.com.


    Click here to learn more. Visit the dedicated forum to share, explore and talk to experts about Microsoft Teams.

    Friday, November 30, 2018 2:57 AM
  • I'll do all of your steps above, asap, and let you know, thank you. I'll put a picture with the error messages. This is not normal mail, it's certified mail. It's in italian.


    • Edited by Miyamoto_89 Friday, November 30, 2018 8:42 AM
    • Edited by Perry-Pan Monday, December 3, 2018 6:38 AM Remove personal informations
    Friday, November 30, 2018 8:28 AM
  • Hi Miyamoto_89,

    How is everything going on with this issue now?

    For security, please remember to remove personal information such as email address before posting in this forum.

    Do you have any anti-virus software running on these PCs? In case the scanning from antivirus software changed this email, we can temporarily close these programs to test the result.

    Any updates, please feel free to post back.

    Regards,

    Perry


    Please remember to mark the replies as answers if they helped. If you have feedback for TechNet Subscriber Support, contact tnsf@microsoft.com.


    Click here to learn more. Visit the dedicated forum to share, explore and talk to experts about Microsoft Teams.


    • Edited by Perry-Pan Monday, December 3, 2018 6:39 AM
    • Proposed as answer by Perry-Pan Tuesday, December 4, 2018 6:33 AM
    Monday, December 3, 2018 6:38 AM
  • Hi Miyamoto_89,

    Any updates with this issue?

    Regards,

    Perry


    Please remember to mark the replies as answers if they helped. If you have feedback for TechNet Subscriber Support, contact tnsf@microsoft.com.


    Click here to learn more. Visit the dedicated forum to share, explore and talk to experts about Microsoft Teams.

    Tuesday, December 4, 2018 6:33 AM
  • Hi, still nothing, unfortunately. I'm the only IT guy in my organization, didn't have got time yet, I apologize.
    Tuesday, December 4, 2018 8:22 AM
  • Hi Miyamoto_89,

    Haven't got time to try the suggestion above, right?

    You could feel free to post back if there are any updates.

    Regards,

    Perry


    Please remember to mark the replies as answers if they helped. If you have feedback for TechNet Subscriber Support, contact tnsf@microsoft.com.


    Click here to learn more. Visit the dedicated forum to share, explore and talk to experts about Microsoft Teams.

    Tuesday, December 4, 2018 11:45 AM
  • For the moment I've just put all of the problematic senders on the Outlook clients in a whitelist. I'll wait 1-2 days and then proceed with the next solutions you posted. I'll let you know asap, thank you.
    Tuesday, December 4, 2018 12:26 PM
  • No problem~

    Regards,

    Perry


    Please remember to mark the replies as answers if they helped. If you have feedback for TechNet Subscriber Support, contact tnsf@microsoft.com.


    Click here to learn more. Visit the dedicated forum to share, explore and talk to experts about Microsoft Teams.

    Wednesday, December 5, 2018 12:57 AM
  • DECEMBER 12TH UPDATE:

    About one week ago I've proceeded with the first of your suggestions, that is to put the address of the digital signature to Safe List in Junk Mail options. It seems to be working, for now. Not a single mail in Junk (these days about 50 mail arrived safely) from December 5th.

    I can consider the problem solved, for now. I still don't understand the reason behind the sudden issue. Since I've modified the settings on the clients one by one, maybe one of them was problematic and I didn't notice. 

    Thanks to everybody for the help!

    • Proposed as answer by Perry-Pan Monday, December 10, 2018 8:44 AM
    • Marked as answer by Miyamoto_89 Monday, December 10, 2018 8:50 AM
    Monday, December 10, 2018 8:39 AM
  • Hi Miyamoto_89,

    Thank you for the update here.

    By the way, it's recommended to mark your reply as the answer so that your solution will benefit other community members who may encounter a similar issue. Thank you for your understanding.

    Regards,

    Perry


    Please remember to mark the replies as answers if they helped. If you have feedback for TechNet Subscriber Support, contact tnsf@microsoft.com.


    Click here to learn more. Visit the dedicated forum to share, explore and talk to experts about Microsoft Teams.

    Monday, December 10, 2018 8:45 AM
  • Done, thank you!
    Monday, December 10, 2018 8:57 AM
  • You are welcome~

    Have a nice day!

    Regards,

    Perry


    Please remember to mark the replies as answers if they helped. If you have feedback for TechNet Subscriber Support, contact tnsf@microsoft.com.


    Click here to learn more. Visit the dedicated forum to share, explore and talk to experts about Microsoft Teams.

    Monday, December 10, 2018 8:58 AM