Troubleshoot “An Unknown Error Has Occurred Error Number 0x800c0133” – Quick Solution

Written By Kumar Raj
Anuraag Singh
Approved By Anuraag Singh
Published On July 18th, 2022
Reading Time 6 Minutes Reading

Outlook Express is one of the most popular email client to manage emailing services. It stores all mailbox data items in DBX file format. But sometimes while working on it, users face some errors like Outlook Express send receive 0x800C0133. It is the common error encountered by almost every Outlook Express users whenever they try to send or receive email.

Now, to bring Outlook Express back in the normal functioning state and resolve Outlook Express not sending or receiving emails issue, it is important to fix this error as soon as possible. As it is the common error faced by almost every user so, it is important to understand the root cause of an unknown error has occurred error number 0x800c0133. Thus, this post will explain both reasons and respective solutions related to this Outlook Express Error number 0x800c0133.

Sometimes, when a user sends or receive an email in Outlook Express, it displays an error message on the screen stating:

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

outlook express error number 0x800c0133

This error generally faced by the users when Outlook Express inbox has become corrupted or damaged. It means Outlook Express data file i.e., DBX file is corrupted. Outlook Express Error Number 0x800c0133 is the most common issue faced by several users that leads to Outlook Express not send or receive emails problem.

Real User Queries Based on Outlook Express Error Number 0x800c0133

“I am using Outlook Express as emailing application from a long time. It was working normally, but from last night I was only able to send email and not receiving. It thought my mailbox would be full so, I delete some of my unwanted emails from my mailbox. After that also I was unable to receive new emails. I do not understand what is wrong with Outlook Express. I think my inbox is corrupted or there is something wrong with the Inbox.dbx. Now, I do not know how an unknown error has occurred error number 0x800c0133 can be corrected without any loss of data.”

“I need help as my Outlook Express not sending or receiving emails from last few days. Whenever I sign in to my account, it starts receiving messages and immediately display an error message on the screen i.e., 0x800C0133 error code with POP3 Port 110. After this error, Outlook Express not send or receive emails. I do not what has exactly happened? If anyone out there can help to solve an unknown error has occurred error number 0x800c0133 situation, then please suggest!!”

Why Outlook Express Error Number 0x800c0133 Encountered?

There are several causes of Outlook Express not sending or receiving emails issue that occurs error number 0x800c0133 and all of them are discussed below:

  1. There is corruption in the Windows registry
  2. If DBX file gets corrupted or damaged, then users also face this error.
  3. A user has not installed Outlook Express email client properly on the local machine.
  4. Size of the inbox.dbx file is greater than the default file size limitation
  5. There is corruption in Windows system files.

How to Solve Outlook Express Error 0x800c0133 Manually?

A user can try both manual methods discussed below to fix Outlook Express error number 0x800c0133 in a cost-effective manner:

Solution 1: Try to Fix inbox.dbx file

  1. First of all, open Outlook Express application on the local machine
  2. After that, move to local folders and choose New Folder option
  3. Then, you have to create a new folder with Temp as a name
  4. Next, transfer all email messages from the Inbox folder to the newly created Temp folder
  5. Now, click on the Browse button and choose the destination location for Inbox.dbx file

After that, you have to follow the steps mentioned below to solve Outlook Express Error Number 0x800c0133

  1. Now, in Outlook Express you need to click on the Tools menu and choose Options
  2. Next, move to Maintenance tab directly to fix Outlook Express problems sending email
  3. At last, click on the store folder >> open store location dialog box
  4. After that, simply exit Outlook Express application
  5. To confirm, simply move the destination location and look for Inbox.DBX file
  6. Then, delete the inbox.dbx file and start Outlook Express application again
  7. Here, you can recreate Inbox folder in Outlook Express mail client
  8. At the end, you can easily move messages from Temp folder to Inbox folder

Solution 2: Repair Corrupt Windows Registry

  1. First of all, type run in the search box and press Enter key to open Run window
  2. Then, the Registry editor will displayed on the screen
  3.  After that, open each folder by following the command below:
    HKEY_LOCAL_MACHINE_Software >> Software >> Microsoft >> Windows >> Current version >> run
  4. Then, you need to choose Outlook Express error 0x800c0133 file
  5. At last, remove this error file simply and restart your system
    This way a user can fix Outlook Express send receive error 0x800c0133 manually without any expert help.


Outlook Express was popular among the users but now Microsoft Outlook has replaced it. It is because it is not compatible with the latest versions of Windows operating system. Apart from all this, Microsoft does not support Outlook Express this anymore. This is the reason users start facing issues while using it. Therefore, it is recommended to switch to some other email client. Outlook is one of the best possible choice for any user as it famous also. Now, to migrate data from Outlook Express, one can take help of a third-party tool named as DBX Converter. It is designed in such a manner that it convert mailbox data in a seamless manner. In addition, it is also best in fixing Outlook Express error number 0x800c0133 in no time.