Outlook Stuck Verifying Data Integrity and Taking Long Time: Fixed

Microsoft Outlook mainly relied on Outlook data files (PST and OST) to store data such as emails, contacts, calendars, notes, and other items. To ensure that this information remains consistent and accessible, Outlook periodically performs a background check, which is known as Data Integrity Verification. It verifies the structure of Outlook data files and checks for inconsistencies that could affect mailbox functionality.

Generally, verification process completes automatically within a few minutes. However, some users encounter situations where Outlook shows “Verifying Data Integrity” message for long time, freezes during startup or Outlook stuck verifying data integrity. It makes your Outlook unresponsive, prevents access to emails, delays synchronization, or repeatedly crashes before opening Outlook.

It can happen with both PST and OST files. Oversized data files, corruption, improper application shutdowns, synchronization failures, damaged Outlook profiles, faulty add-ins, disk-related issues, and insufficient system resources are the major causes of this issue.

In this write-up, you’ll learn meaning of Outlook data integrity verification, why Outlook stuck verifying data integrity, symptoms, effective troubleshooting methods, and automated solution to recover mailbox data from affected data files without losing any information.

What Does “Verifying Data Integrity” Mean in Outlook?

Data Integrity Verification is a built-in function provided by Outlook to check consistency and reliability of mailbox data stored in PST and OST files. During this process, Outlook scans both the data file structure, missing references, folder inconsistencies, syncing issues, or corruption that could impact mailbox.

Outlook may start verifying data integrity after:

Outlook closes forcefully or unexpectedly.
Computer shut down suddenly.
PST or OST file becomes corrupted or damaged.
Outlook detects mailbox inconsistencies.
Outlook data file has reached the maximum size
Synchronization issue between Outlook and Exchange server.

The purpose of “Outlook Verifying Data Integrity” process is to make sure your Outlook data files remain healthy and accessible.

Symptoms of Outlook Stuck Verifying Data Integrity

Before knowing anything, let’s understand the symptoms when Outlook verifies data integrity taking a long time, or stuck during the process.

Outlook showing “Verifying Data Integrity” screen for a long time.
Outlook frozen with this message.
Application becomes unresponsive.
Mailbox folders fail to load.
Email syncing process stops or not working.
Outlook repeatedly crashes after launch.
Slow Outlook performance when opening emails or folders.

Why Is Outlook Verifying Data Integrity Taking a Long Time?

Several factors can cause Outlook stuck while verifying data integrity. Some of the major issues are discussed below:

Damaged Data Files: Corruption is the common issue linked with this problem. Outlook crash, power failures, malware attacks, storage device issues can damage and make your files inaccessible.
Large File Sizes: As mailbox grows over time, Outlook data files become larger. And Outlook requires additional resources to verify and process the large files. These files can increase startup time, cause delays in verification, affect performance, and increase the risk of corruption.
Outlook Did Not Close Properly: If you close Outlook forcefully through Task Manager, or closed unexpectedly due to system crash then during the next startup Outlook starts verification process to check for potential inconsistencies.
Damaged Outlook Profile: A damaged Outlook profile can also interfere with startup operations.
Faulty Add-ins: Wrong third-party add-ins installation can conflict during the process which may cause Outlook stuck verifying data integrity.
Exchange or Microsoft 365 Synchronization Problems: If your account is connected with Exchange or Microsoft 365, then this problem occurs due to syncing issue.
Disk or File System Errors: Bad sectors, storage corruption, or file system issues can prevent Outlook from reading and analyzing mailbox data.

How to Fix Outlook Stuck Verifying Data Integrity?

We can resolve this issue after understanding the root cause of this problem, which we have explained above. Now let’s resolve this issue:

Method 1: Wait for Completing Verification

If your mailbox is large then Outlook may require time to complete the process. Before following any technique:

Leave Outlook open for some time.
Analyze disk activity through Task Manager.
Don’t restart Outlook repeatedly.

If it doesn’t work and Outlook is stuck for long hours then proceed with next method.

Method 2: Restart Application

Close your Outlook completely using Task Manager and restart it.

Close Outlook.
Go to “Task Manager (CTRL + SHIFT + ESC)”.
Check the running process of Outlook.
Right-click and choose “End Task”.
Restart your computer.
And open Outlook again.

Method 3: Try to Launch Outlook in Safe Mode

Safe Mode helps to start Outlook without any connected add-ins. You can try this method. If Outlook works successfully, then remove all unwanted and problematic add-ins:

Open “Run” with “Windows + R” keys.
Type: outlook.exe /safe
Hit the “Enter” icon.
If your Outlook opens normally here, then disable all unnecessary add-ins.

Method 4: Rebuild OST File

Damaged OST file is the main cause of “Outlook stuck verifying data integrity” issue. So, we can recreate an OST file to resolve it by following these steps:

Important Note: This method works well when all your mailbox data is available on the mail server as Outlook will download it again into new OST file. However, if your old OST contains unsynchronized data, then renaming it can make it orphaned and inaccessible, potentially resulting in data loss.

Close your Outlook.
Locate the OST file.
Rename it.
Restart Outlook.

A new OST file will be created automatically and synchronized with the server.

Method 5: Check and Reduce Oversized Mailbox

If the process takes a long time for hours and running on screen, then it could be due to large mailbox size. Because Data Integrity Verification process can take time for loading and analyzing large files.

You can decrease the mailbox size manually by:

Deleting unnecessary emails.
Removing large attachments and saving them locally.
Empty Trash and Junk folders.
Archive old emails into separate data file.
Compact PST file.

But what if your application freezes due to big files? It mainly happens due to large PST file size, so you can use SysTools PST Splitter to split your file into smaller files. This software will help you to manage files smoothly by size, date, folder, year, category, subject, email ID, etc. It works without even Outlook application. Try demo version to minimize your file size.

Method 6: Fix Outlook Stuck Verifying Data Integrity by Creating New Profile

Sometimes damaged profile can cause Outlook to get stuck for verifying data integrity process. Here are the steps to create a fresh profile.

Open Control Panel.
Choose “Mail”.
Hit on the “Show Profile”.
Select the “Add” option.
Make a new profile.
Configure the account and set it as default profile.

Method 7: Repair PST File with ScanPST

For PST related corruption, Microsoft provides built-in Inbox Repair Tool to repair minor corruption.

Important Note: Create a backup copy of your PST file.

Close Outlook.
Locate and start your SCANPST.EXE.
Select PST file.
Start the scan process.
It will detect the errors.
Fix it and restart Outlook.

Method 8: Check Hard Drive for Errors

Use Windows disk diagnostics to identify storage issues.

Command: chkdsk C: /f /r.

And restart the system (if prompted).

Method 9: Temporarily Disable Antivirus

Sometimes antivirus software affects and disturbs your data file headers, which can damage them or interfere with the scanning process. So, disable them and then start your application.

What If Outlook Remains Stuck After All Fixes?

If nothing works and still Outlook stuck during verifying data integrity process, then using an automated solution is the only right way.

OST file corruption is the major issue when Outlook takes longer time. And once OST becomes damaged there is no possible manual way available to restore data from damaged or inaccessible files.

You can use SysTools Outlook OST Recovery Tool to restore complete mailbox into healthy format. It can easily recover deleted emails from OST file including other items such as emails, contacts, notes, journals, calendars etc. Download the demo version now.

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Also, ScanPST.exe is a good option to fix corrupt PST file, but it can only fix minor corruption. For severely damaged files, go for the SysTools Outlook Recovery Tool. It can also recover data into healthy format including permanently deleted data.

Tips to Prevent Outlook Data Integrity Problems

To avoid errors in Outlook in the future, follow these tricks:

Always close your application properly.
Archive your old emails automatically.
Update Outlook and Windows versions.
Back up Outlook data files periodically.
Keep PST file within recommended size limits.

Conclusion

Outlook Stuck Verifying Data Integrity when it detects potential inconsistencies and issues within PST and OST file(s). It can happen due to large data files, improper Outlook shutdowns, synchronization issues, profile corruption, add-in conflicts, or storage problems, PST and OST file corruption. Fortunately, we can resolve this issue by opening application in safe mode, profile recreation, restarting Outlook, rebuilding OST file, and optimizing file size.

If manual troubleshooting fails, then try automated solutions to fix issue without losing data. Also, you can connect with us through live chat support for any query.