Summary: This blog sheds light on the error “Mailbox exceeded the maximum number of corrupted items” that arises while migrating from one Exchange version to another. It explains the reasons behind the error and some common fixes to resolve the error. It also highlights a third-party Exchange Database Repair software as the ultimate solution to fix various Exchange issues.
Migrating an existing emailing setup, such as Exchange, from one version to another is a complicated task. It requires proper planning, expert execution, and testing to accomplish it successfully. Although automated tools have made this task relatively simpler, there are still a number of things that needs to be taken care of manually. The slightest of error during migration may turn one or more mailboxes corrupt. Further, other complicated errors could arise which may hamper the entire migration process.
One of the cryptic error messages that users sometimes face during Exchange migration is as follows,
“This mailbox exceeded the maximum number of corrupted items that were specified for this move request.”
When this error comes up, it may disrupt the entire migration process. Until there is a solution at hand, the migration process comes to a temporary stop. This, in turn, impacts mailbox connectivity and all user mailboxes on the server. Thus, rectifying whatever causes this error should be the top priority in such a scenario.
What causes ‘Mailbox Exceeded the Maximum Number of Corrupted Items’ error?
Before attempting to resolve this error, it is essential to first find the root cause. That will prove beneficial in preventing the error from occurring again. Below are the some causes that may trigger this error:
• It is clear from the error message itself that the error occurs when the number of corrupt mailboxes being migrated exceeds the set limit. This is due to the fact that the Exchange server allows only a finite number of corrupt mailboxes to be a part of the migration. If the actual number of corrupt mailboxes is more than the set limit, the migration process is paused or get stuck midway.
• If the Exchange server itself has turned corrupt, it needs to be isolated. This error occurs in such a case too when a corrupt mailbox has damaged emails or attachments. Such a mailbox isn’t allowed to migrate. However, if issues are faced while isolating such a mailbox, the server itself can turn corrupt. Therefore, giving rise to the error.
The error in focus is commonly observed while migrating Exchange server 2010 and other versions of Exchange. It may also occur during the migration between Exchange server and Office 365 with hybrid deployment facility.
Now that we have discussed the possible root causes, let’s now look at resolutions to fix this ‘mailbox exceeded the maximum number of corrupted items’ error.
Solutions to Fix ‘This mailbox exceeded the maximum number of corrupted items’ Error
There are a number of ways and solutions to overcome this error. Some common free fixes are as follows,
1. Increase the limit of corrupted mailboxes by using PowerShell Commands
PowerShell enables you to execute complex internal commands that can alter the way Exchange server migration takes place. However, you need to have some expertise for executing such commands. Any mistake may worsen the damage or lead to permanent data loss.
Follow the steps below to increase the set limit of corrupted mailboxes:
a. Launch PowerShell with admin rights
b. Type the command Get-MoveRequest and hit Enter. All mailboxes that failed to migrate will be listed
c. Execute the command Set-Move Request with value 100
Note: You also need the -AcceptLargeDataLoss switch, if you are setting the limit of “BadItems” anywhere close to 50.
2. Identify mailbox corrupt items and remove them from isolation
This is not a preferable solution as it turns off the isolation feature, allowing corrupt mailboxes to be a part of the migration. However, it can be used as a last resort. Follow the steps below:
a. Get the GUID of the corrupted mailboxes by executing the command Get-mailbox-statistics-identity
b. Press F1
c. Find the registry entry
HKLM\SYSTEM\CurrentControlSet\Services\MSExchangeIS\Private-<db-guid>\Quarantinemailboxes\ <the mailbox guid>
d. Change the key mentioning GUID
e. Restart IIS with the command iisreset
This should remove mailbox corrupt items from isolation.
3. Repair damaged Exchange server database files (EDB) with ESEUTIL
The inbuilt Exchange ESEUTIL command line utility is often used by administrators to repair inaccessible or corrupt EDB files. The utility can help carry out hard as well as soft recovery from offline Exchange server. However, to use this option, you should have administrator rights as well as technical know-how of using the utility.
To repair the damaged database, ESEUTIL command is used with the /p switch (hard recovery). This is followed by ESEUTIL/d command to defragment the repaired database. Lastly, the integrity of the database is checked with the ISInteg command. However, hard recovery via ESEUTIL can cause data loss. Thus, use it if you are ready to accept data loss. Otherwise, you may follow the recommended solution discussed below.
Although the above fixes are free of cost and may work, they come with a fair share of risk. In case a wrong step is taken, you may end up creating more damage than repair. Thus, if you’re not confident about applying the free fixes, it is suggested that you should opt for an automated third-party tool, such as Stellar Repair for Exchange for repairing the corrupt Exchange mailbox database.
The Exchange Database Recovery software deftly handles EDB corruption issues and repairs damaged EDB files to recover all mailbox contents, such as mails, attachments, contacts, calendars, tasks, etc. The tool allows saving recovered mails in a variety of file formats, such as PST, MSG, EML, HTML, RTF, and PDF. With several other beneficial features to assist you, this software serves as an answer to all Exchange corruption issues, including “this mailbox exceeded the maximum number of corrupted items” error.
Thus, you can use the software to safely extract mailboxes from EDB file and save them in PST or export directly to live Exchange or Office 365, without encountering any Exchange error.
The Bottom Line
Now that you are acquainted with the free fixes to resolve Exchange server issues, you can leverage them as and when required. However, the downside is that technical expertise is an important pre-requisite in this case. Therefore, if you are less confident about running the PowerShell commands or are looking at a non-lengthy and hassle-free recovery process, then Stellar Repair for Exchange would be the best bet. It’s a GUI-based software that makes mailbox export and migration process easier and convenient.