Unknown error has occurred – 0x800C0133

Unknown error has occurred – 0x800C0133

0x800C0133 appears in Outlook Express while receiving/downloading email from POP3 email account. This error is thrown by Outlook Express after failing to store the downloaded email in its data store file i.e. Inbox.dbx file.  As discussed in Access mailbox using Command Line Client, POP3 email clients download email one by one and stores it to the underlying data file, now what happens here is that after downloading email Outlook Express try to store it in Inbox.dbx, and now if the Inbox.dbx file is either corrupted or it’s 2GB capacity is reached then it will not allow to store an email in it and will throw an unknown error (Unknown error has occurred – 0x800C0133).

Error Sample

An unknown error has occurred. Account: ‘mail.domain.com’, Server: ‘mail.domain.com’, Protocol: POP3, Port: 110, Secure(SSL): No, Error Number: 0x800C0133

Troubleshooting the Issue

•  First of all check the size of Inbox.dbx file

In Outlook Express go to Tools – Options – Maintenance and then click “Store Folder…” button, and open the path shown there. Check the size of Inbox.dbx, if its size is around 2GB then its capacity is filled or else it has been corrupted. Irrespective of whether it has been corrupted or 2GB filled, we will move all the messages to the new folder and will create a new blank Inbox.dbx file.

• Create a new folder in Outlook Express by right clicking “Local Folders” and then clicking “New Folder” and provide it a name e.g. “Inbox Old”.
• Exit Outlook Express
• Now, open the data store folder of Outlook Express as discussed in step 1.
• Rename “Inbox.dbx” file to “Inbox1.dbx”
• Rename “Inbox Old.dbx” to “Inbox.dbx”
• Rename “Inbox1.dbx” to “Inbox Old.dbx”
• Start Outlook Express. You will see a blank Inbox folder and all the emails of Inbox will be under Inbox Old folder.
• Now, emails will start downloading as normal.

In case if the Inbox.dbx or any other dbx file is corrupted or 2GB issue, then you will have to consult some third party dbx recovery software for recovering emails from it and to resolve 2GB issue.