Fix Outlook Error 0x800cccob

People often think that the Outlook Error 0x800cccob occurs while sending or receiving an e-mail, mostly when the user tries to send an e-mail, so it must be a server problem, but it is nothing but a myth. A myth that almost every user considers true until the time correct piece of information reaches him, now the question becomes – what the reason is, behind the occurrence of the Outlook Error 0x800cccob, what the causes are!

“Error Message: An unknown error has occurred. Account: ‘’, Server: ‘’, Protocol: SMTP, Port: 25, Secure (SSL): No, Error Number: 0x800CCC0B”

Here are the causes –

  • The problem may occur due to misconfigured e-mail client.
  • Due to the fact that ISP of the computer one is using is blocking access to port 25.
  • There may be a DNS problem with one’s ISP.
  • There is an error with SMTP on one of the servers, i.e., the e-mail provider is not allowing messages to be sent via (SMTP) without server authentication.
  • Make sure there is no corruption in the registry file your computer possesses. If there is something wrong with registry entries, then it is better first fix it by using Outlook PST Repair Tool. Then, move ahead, restart your Outlook and try sending an e-mail again, and see if you find any problem in that. If the problem persists, keep reading the article.
  • Damaged Outlook PST also may push the Outlook SMTP Error number: 0x800cccob, so if one figures out that the problem is due to damaged Outlook PST, then again, the same tool – Outlook PST repair tool, this tool is especially designed for such problems. Download this tool, install and launch, you will be given simple instructions. After that, check again by restarting your Outlook, if it works correctly.

One can also try these manual steps to fix Outlook Express error code 0x800cccob –

  • Go to the Outlook Express, navigate to Tools > Accounts.
  • The user has to select the account, and then click
  • Then, one has to navigate to the servers tab, go to Outgoing Mail Server and check the server requires authentication. Finally click OK.
  • Just try sending an e-mail, and see if the problem persists.

Compatible with Outlook 2000, 2002, 2003, 2007, 2010, 2013 and supports Windows 8, 7 (32-bit/64-bit), Vista (32-bit/64-bit ), 2003, XP, 2000, NT4 (SP6).

Those who find themselves unable to perform the manual steps, can directly go for the Outlook PST Repair Tool, it will fix your problem without having to apply yourself hard into the methods.


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