Fix Exchange Server Error 451, 452, 471

Exchange Server Errors 451, 452 and 471 are unrelated errors and are caused due to issues on Exchange server or its database, but they result in the same problem – Mails not received through MS Outlook. In this article, we present the causes for these errors, various error messages shown and the fixes for those. though manual methods are good at resolving the errors, if the error is not fixed, then resolve through an automated solution.

Let us discuss each error, individually and find its solution.

Exchange server Error 451

When a sender mails an email through MS Outlook, the email client first connects to Edge Transport Server. The Edge Transport server links to the Edge Transport server at the recipient’s end through the Internet and transmits the email.

The following figure depicts the Email Relay Environment:

The error is experienced when the Email Relay environment is affected due to temporary exchange server issues like as mail limits exceeded, DNS errors, unreachable mail servers, etc., and Exchange server error can be experienced due to a discrepancy on Sender Exchange or Receiver Exchange server. The error message is flashed as:

Email delivery error due to Event ID 451 is possible due to multiple issues. Resolve the problem after a thorough examination of the error message and the email logs.

  • 451  You have exceeded your messaging limits
  1. To combat abuse or spamming on the Mail server, most servers have limited number of connections allowable for any email account. Once the user exceeds this connection limit, it results in an error.
  2. At times, the user sends too many messages in short period which also results in an error: “451 Requested action aborted: This mail account has sent too many messages in a short amount of time. Please try later.”
  • Temporary Server Error. Please try again later
  1. The error is a result of DNS issues on the sender server, due to which the sender is unable to establish the connectivity
  2. Improper configuration of MX Records for the domain
  3. Incorrect routing of emails as a result of local server resolver issues may also result in Error 451
  4. Understand the exact cause of the problem by checking the Mail Server Logs. 

Possible Solutions to resolve Exchange Server Error 451:

  1. Increase connection limit in Mail Server. Enhance the “smtp_accept_max_per_host” configuration limit to fix the error
  2. Limit the number of emails for every user on Mail Server. Edit the values for individual email accounts and increase the threshold for particular users who need to send more emails
  3. Set the MX Records as Local mail servers for a specific
  4. Resolve the MX Record query. Verify and ensure that the primary mail server priority is set as 0, and MX resolves to the correct server
  5. Deploy the automated software like Stellar Mailbox Exchange Recovery software and fix the error, in case all the above solution fail.

Exchange Server Error 452

Exchange server Database consists of Server data files, and these include EDB files, Log files and STM files. When the three files connect with each other, then their connection group is named as Storage Group.

Following Image depicts the MS Exchange Server Database files

Exchange server Error 452 occurs during Exchange Database Recovery. Exchange Server error 452 results in a delay of Online Database Recovery caused due to a missing Log file in the temporary folder. The following error message flashes:

Exchange Database Recovery error occurs due to missing log files. There are several reasons for missing log files: a hardware failure, damaged or corrupted the log files, and in some cases, the log files go missing:

  1. The backup program specifies a Log file, but the Temporary folder does not contain that Log file
  2. Loss of Log files due to hardware failure
  3. Error 454 generates when the database is repaired with Eseutil/p command. It signifies that restore is not possible in the event of missing log files.

Possible Solutions to resolve Exchange Server Error 452:

  1. Verify if the Log Files have moved or these are deleted. Move the Log Files back to their original location if the Log Files have moved. Restore the Log files from backup, and specify these files in the Event Massage
  2. After successful relocation and restoration, run the Eseutil commands Eseutil/cc or Eseutil/cc/t and determine a different location for the Logs. Mount the Exchange database after moving the Logs
  3. Alternately, restore the complete Exchange database from backup and run the command Isinteg-fix utilizing ‘Move Mailbox to move the data to the new blank database.’
  4. If the Exchange Server Error 452 persists, then look for automated tools for Exchange Database Repair

Exchange Server Error 471

Exchange Administrators define the Storage space on the database based upon the organizational requirement due to which the Exchange server database has pre-defined space. Admins also define the Anti-spam rules by Content Filtering Policies of the organization.

Following Image depicts the MS Exchange Anti-spam filtering:

Sometimes, Exchange server encounters rollback operation issues on the database, as specified in the event description and are unable to take the future updates. In that case, there is rejection in rollback operations and the server experiences Exchange Server error 471. Until the problem is not resolved, there are no updates possible on Exchange database. Following issues lead to the rollback operations:

  • Permission issues on Exchange server database
  • Lack of space
  • Disk I/O error
  • The problem with Local Anti-spam Filter

The error message is flashed as:

Following Error Codes are generated with Exchange Server Error 471:

  • Error -510 (0xfffffe02)JET_errLogWriteFail:

An attempt to write the Log file n database fails and leads to the error. Possible Causes: Permission issues, space problems

  • Error -1022(0xfffffc02)JET_errDiskIO: 

The Disk I/O issue stops Exchange server to access the requested page in the database. Possible Cause: Disk I/O Error

  • Error on mail server due to an issue on mail server often caused by conflicting local anti-spam filter permissions

Possible Solutions to resolve Exchange Server Error 471:

Find the reasons behind the permission issues and other issues to analyze these issues and address.

  • Run the command – chkdsk/f/r
  • Disable outgoing antispam filter from the server. In case using remote mail exchange, contact the SMTP service provider or server administrators
  • If the Exchange Server Error 471 persists, then resolve the error with Stellar Exchange Database Repair software
Free download


The most significant nightmare for Exchange Administrator is Exchange server experiencing error codes due to which the database becomes unresponsive. Though the possible solutions and the backup can rectify the error and bring the database back to normal state, it may not always be the right solution. In fact, resolving the error with the automated software like Stellar Mailbox Exchange recovery software helps to reduce the downtime and rescues Exchange Admins from unwanted disasters. The software has a grand capacity to extract single as well as multiple mailboxes to working MS Outlook including all folders and the attachments

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