The dreaded 0x800CCC0F sending error

Anonymous
2022-07-21T19:36:33+00:00

I am now running Microsoft® Outlook® 2016 MSO (Version 2206 Build 16.0.15330.20260) 64-bit, on Windows 8.1; I had been running the 32-bit version, but I upgraded to 64-bit in an attempt to resolve this error on sending: "Task '[email account] - Sending' reported error (0x800CCC0F): 'The connection to the server was interrupted....' "

My Outlook is configured for two IMAP accounts, both with Google - one is a GMail account, the other is Google Workspace account that services email for my domain (59plymouth.net). Outlook is also configured for a work Exchange account.

A few weeks ago - not sure, but I think after a reboot, and when Windows updates were applied - both IMAP accounts stopped sending. The Exchange account continues to work without issue.

The updates were July updates - 5015874, 50156268, and 50154633. Suspecting these, I backed them out and disabled updates. No luck. I then did the Outlook 64-bit upgrade. NADA.

I'd suspect Google, but my iPhone continues to work without issue for both accounts; so does my iPad (which also talks to my Exchange account).

I'm not sure where to go from here. And ideas about how to further diagnose?

adTHANKSvance,

Dan

Outlook | Windows | Classic Outlook for Windows | For business

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  1. Anonymous
    2022-09-30T14:00:27+00:00

    I have been going back through some reports with the errors:

    “The connection to the server was interrupted.”

    “Your server unexpectedly terminated the connection.  Possible causes include server problems, network problems, or a long period of inactivity.”

    One cause I found is if TLS 1.3 got configured on the machine. I am working on a Known Issue to document it but sharing here in case it can help. I don't know yet what is setting this regkey.

    1. This issue will occur if your machine was updated to have TLS 1.3 configured.  To workaround the issue do the following:
    2. Click Start, search for Regedit and open the application
    3. Navigate to this path in the registry: Computer\HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocol
    4. Before you make any change, right click on the Protocols key and Export it for a backup just in case.
    5. If under Protocols you see TLS 1.3 delete that key and its sub keys.

    This is how it should look from my Win11 computer:

    Image

    Here are a couple other forum threads where they had the same issue for more context and other investigation steps:

    Outlook 2016 connectivity to gmail lost suddenly and cannot figure out - Microsoft Community

    Outlook Cannot Send Emails to Certain Accounts - Microsoft Community

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  2. Anonymous
    2022-07-21T20:47:42+00:00

    Unfortunately, I can't answer what you're running into on the Google side of things but you may want to try using a private browser session (or a different browser) to see if that changes anything. If not, you'll need to get a hold of Google support

    FWIW - the attached screenshot that I just took before posting this response, shows what I see on my account

    .

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  3. Anonymous
    2022-07-21T20:45:29+00:00

    Waydaminit! That's all I saw with my Google Workspace account, for which I am administrator; I have to figure out how to enable 2-Step Verification with that. However, when signed into my GMail account, I *do* see 2-step verification. I'll work on that account first. Stay tuned, and thanks!

    Dan

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  4. Anonymous
    2022-07-21T20:29:41+00:00

    Thanks Karl! I'm trying it now. However: under #1 above, support.google.com says this:

    Allow 2-Step Verification

    1. Open your Google Account.
    2. In the navigation panel, select Security.
    3. Under “Signing in to Google,” select 2-Step Verification and then Get started.
    4. Follow the on-screen steps.

    ...but for (3), I don't see 2-Step Verification as an option under "Signing in to Google". There's simply an option to change my password, which first prompts me for my current password. Am I missing something?

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  5. Anonymous
    2022-07-21T20:10:43+00:00

    Hello Dan

    Hi, I'm Karl and will be happy to help you today.

    What you need to do is enable 2 factor authentications on your Gmail account and then generate an <App Password> to be used as the password or the email account in Outlook. This is a Google change that took effect June 1, 2022

    Recap of steps

    #1 - enable 2 factor authentication for the GMail account

    Turn on 2-Step Verification

    https://support.google.com/accounts/answer/1858...

    #2 - generate a Google <App Password> for this account (do not turn off 2FA fter generating the <App Password>)

    Sign in with App Passwords

    https://support.google.com/mail/answer/185833?h...

    #3 - Change the password in Outlook for the email account to use the <App Password> you generated in step #2 (suggest using copy ;n paste - the <App Password> is a contiguous 16 character string - no spaces)

    *** for an account already configured in Outlook, to change the email account password

    #4 - press CTRL+ALT+S to bring up the Send / Receive dialog

    #5 - Select the <Group> (most people only have one) --> click on ,<Edit>

    #6 - Select the GMail account --> click on <Account Properties>

    #7 - paste the <App Password> for the email account password

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