For the question of Outlook error code 0x80040900, the answer is that it can be solved by checking account settings, repairing data files, clearing caches, or closing third-party plug-ins. 1. Check whether the account settings are correct, including username, password, server address, port number and encryption method; 2. Use the SCANPST.EXE tool to repair the corrupted .pst or .ost data files, rebuild the configuration file if necessary and import the old data; 3. Delete the .ost file to clear the cache and resync the account; 4. Enter safe mode to disable the plug-in or temporarily close the firewall and antivirus software to eliminate interference. In most cases, the above steps can be effectively solved.
Outlook error code 0x80040900 Usually when you try to send or receive emails, prompting "There is a problem with the send/receive settings". This problem may be caused by configuration errors, corruption of data files, or an exception in the account synchronization. Don't worry, in most cases, you can solve the problem in the following ways.

Check whether the account settings are correct
This error is sometimes caused by inaccurate account settings in Outlook, especially SMTP or POP/IMAP configuration errors.
- Confirm that your username and password are correct
- Check whether the server address is spelled incorrectly (for example, imap.example.com is written as imap.exmple.com)
- Ensure that the port number and encryption method are consistent with the requirements of the email service provider
If you are not sure how to set it up, you can go to the official website of your email service provider to find the "Outlook Setting Guide" or "SMTP Setting Instructions".

Repair or recreate Outlook data files
Outlook uses .pst
or .ost
files to store mail data. If these files are corrupt, it may also cause error 0x80040900.
You can use the repair tools that come with Outlook:

- Find the
SCANPST.EXE
tool in the Outlook installation directory (usually inC:\Program Files\Microsoft Office\root\OfficeXX
directory, XX is the version number) - Run it and select the corresponding data file for scanning and repair
If the fix is invalid, you can try:
- Create a new Outlook configuration file (create it in Control Panel > Mail)
- Import old data into new configuration file
Clear cache and resync your account
Outlook caches a large amount of account information locally, and sometimes these caches can go wrong.
You can try to clear the cache:
- Close Outlook
- Go to
%localappdata%\Microsoft\Outlook
folder - Delete or rename
.ost
files (if it is an Exchange account) - Restart Outlook and wait for the account to resync
Note: Deleting the .ost
file will not affect the mail on the server, but will clear the local cache and need to be downloaded again.
Temporarily close third-party plug-ins or firewall software
Some security software or Outlook plug-ins may interfere with the email sending/receiving process.
You can try:
- When starting Outlook, hold down the Ctrl key and click the icon to enter "Safe Mode", and disable all plug-ins
- If the problem disappears, it means it is a problem with a plug-in. Just troubleshoot one by one
- Temporarily close the antivirus software or firewall to test whether to recover
Basically these common solutions. Select the operation steps according to the specific situation. Most of the time, reconfiguring the account or repairing the data file can solve the problem.
The above is the detailed content of How to fix Outlook error 0x80040900. For more information, please follow other related articles on the PHP Chinese website!

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