You may see an error stating Outlook failed to update headers for IMAP folders. This prevents you from seeing new email in your IMAP account. The error is typically caused by a corrupted local data file or a conflict with your email provider’s server settings. This article explains the root cause and provides steps to resolve the issue and restore your email flow.
Key Takeaways: Fixing the IMAP Headers Update Error
- File > Account Settings > Repair: Forces Outlook to rebuild the connection to your IMAP server and can fix configuration corruption.
- File > Account Settings > Data Files > Remove: Deletes the local Offline Outlook Data File (.ost) so Outlook can download a fresh copy from the server.
- Ctrl + Right-click Outlook taskbar icon > Exit: Ensures Outlook is fully closed before deleting local files, preventing data lock errors.
Why Outlook Cannot Update IMAP Folder Headers
IMAP, or Internet Message Access Protocol, syncs email between a server and your Outlook client. Folder headers are metadata that tell Outlook about the contents of each folder, like message counts and subjects. When Outlook fails to update them, it cannot accurately display what is on the server.
The primary cause is a corrupted local Offline Outlook Data File, known as an .ost file. This file caches your mailbox data for offline use. If this file becomes damaged, Outlook cannot properly communicate with the IMAP server to fetch updated header information. This corruption can happen due to an interrupted sync, a sudden Outlook or Windows closure, or disk errors.
Server-Side and Configuration Factors
Less commonly, the problem originates from the email server. The server may be undergoing maintenance, experiencing high load, or have reached a storage limit for your account. Incorrect IMAP server settings in Outlook, like an outdated password or wrong port number, will also prevent header updates. Antivirus or firewall software that scans email traffic can sometimes interfere with the IMAP connection as well.
Steps to Resolve the Header Update Failure
Follow these methods in order, starting with the simplest repair.
Method 1: Repair Your Account
- Open the Account Settings dialog
In Outlook, go to File > Account Settings > Account Settings. - Select your IMAP account
On the Email tab, click to highlight the IMAP account showing the error. - Initiate the repair
Click the Repair button above the list of accounts. Follow the on-screen prompts, which may include re-entering your password. This process refreshes the connection settings. - Restart Outlook
Close and restart Outlook to see if the folder headers now update correctly.
Method 2: Recreate the Local Outlook Data File
If repairing the account does not work, the local .ost file is likely corrupted and must be rebuilt.
- Close Outlook completely
Click the X to close Outlook. Then, check the system tray near the clock. If the Outlook icon is there, right-click it and choose Exit. You can also press Ctrl + Shift + Escape to open Task Manager and end any Outlook processes. - Open Data File Settings
Reopen Outlook and go to File > Account Settings > Account Settings. Switch to the Data Files tab. - Remove the old data file
Select the data file associated with your IMAP account. It will typically have (IMAP) in the name. Click the Remove button. Confirm any prompt. This only deletes the local cached copy; your emails remain safe on the server. - Restart and resync
Close and restart Outlook. It will automatically create a new, empty .ost file and begin downloading all folder headers and messages from the IMAP server. This initial sync may take some time.
If the Error Persists After Standard Fixes
Outlook Still Shows “Failed to Update Headers” After Rebuilding .ost
The issue may be with your IMAP account settings or the server. First, verify your server settings. Go to File > Account Settings > Account Settings, select your account, and click Change. Double-check the incoming mail server name, port (usually 993 with SSL), and encryption method. Your email provider’s support site has the correct settings. Next, temporarily disable your antivirus email scanning feature and test again.
Only One Specific IMAP Folder Has the Problem
A single corrupted folder on the server can cause this. Log in to your email account via your provider’s webmail interface. Try moving the emails from the problematic folder into a new folder you create in webmail. Then, in Outlook, use Method 2 to delete the local .ost file. Upon resync, the old corrupted folder may be empty and the new one will populate.
Error Occurs Intermittently on Multiple Devices
If you get the error on Outlook for Windows and also on a mobile app, the source is almost certainly the email server. Contact your email provider’s support. There may be a service issue, or your account may have exceeded a storage or connection limit defined by the provider.
IMAP Error Resolution Methods Compared
| Item | Account Repair | Rebuild .ost File | Server-Side Check |
|---|---|---|---|
| Primary Action | Runs Outlook’s automatic connection fix tool | Deletes and recreates the local cached mailbox file | Verify settings via webmail or contact provider |
| Data Risk | None | Requires redownloading all email data | None |
| Best For | Recent configuration or password errors | Persistent errors, suspected file corruption | Errors across multiple devices or clients |
| Time Required | 1-2 minutes | 5+ minutes for initial resync | Varies by provider response time |
You can now fix the Outlook failed to update headers error by repairing your account or rebuilding the local data file. If problems continue, check your IMAP server settings and review your email provider’s status. For advanced management, use the Send / Receive Groups dialog under Send / Receive tab > Send/Receive Groups > Define Send/Receive Groups to adjust sync settings for specific folders.