“Unknown error, error number: 0x800c0133” When Sending or Receiving E-mail in Outlook Express

Solution When you try to send or receive messages using Outlook Express, you may receive error message as below.
“An unknown error has occurred. Account: ‘Example’, Server: ‘example.mail.domain.com’, Protocol: POP3, Port: 110, Secure (SSL): No, Error Number: 0x800C0133 “


  1. All the mail disappear
  2. Unable to download emails
  3. E-mail message could not be sent.


This behavior can occur if the Folders.dbx file is missing, damaged, or using the read-only attribute. Usually it will happen at inbox.dbx.


Try to restart the computer, if the problem persists, please follow the following steps.

the Inbox.dbx file:

  1. Go to “Tools” > “Options” > “Maintenance” tab > Click “Store Folder”. It will reveal the location of your Outlook Express files.
  2. Close Outlook Express, goto the location mentioned above. You may copy the location and paste it in the “Start” > “Run” and click “Ok”.
  3. Rename “inbox.dbx” to “oldinbox.dbx” or name that you prefer.
  4. Restart the Outlook Express, This creates a new inbox.dbx file automatically.

Recovery old emails
You may recover back the old emails by try the following, if they are not corrupt or damage.

  1. In Outlook Express, right click on the local folders icon in the folder list.
  2. Click on New Folder, named it to “Old Inbox”.
  3. Search for oldinbox.dbx.
  4. The old emails should be inside the oldinbox.dbx right now.

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