How to Fix the Message Store has Reached its Maximum Size Error in MS Outlook?

In the digital age, where communication is predominantly conducted through emails, text messages, and various messaging platforms, encountering storage issues is not uncommon. Since MS Outlook is the most popular email client amongst all, it is the most affected application. One of the prevalent issues that users face is the dreaded error that the message store has reached Its maximum size in MS Outlook.

This error message can appear in various forms depending on the messaging platform or email client you’re using, but its implications are the same: your message storage has hit its limit, hindering your ability to send, receive, or store new messages. In this comprehensive guide, we’ll delve into the causes behind this issue and provide detailed steps to resolve it.

Understanding the Error Codes:

Before delving into the troubleshooting steps, it’s essential to understand the error message and the different error codes associated with it. MS Outlook mostly generates an error code whenever an error occurs. This code can help you to understand the actual cause of the error through which we can proceed with the repairing process in that direction. Depending upon the messaging platform or email client, you might encounter variations of this error messages. Some common error codes include:

Error Code 0x8004060c (Outlook): This error code typically appears in Microsoft Outlook when the MS Outlook PST file reaches its maximum storage capacity.

Error Code 0x8004210E (Outlook): Another Outlook-specific error code, indicating that the mailbox has reached its maximum storage limit.

Error Code 552 (SMTP): This error code is commonly encountered in SMTP (Simple Mail Transfer Protocol) servers, indicating that the recipient’s mailbox has exceeded its storage quota.

Error Code 0x800CCCD2 (Outlook Express): Specific to Outlook Express, this error code suggests that the message store has reached its maximum size.

What Causes Outlook Message Store to Have Reached Its Maximum Size Error?

Several factors can contribute to the occurrence of this error, including:

Limited Storage Quota: Most messaging platforms and email clients impose storage quotas on user accounts to manage server resources efficiently. When your mailbox or message store surpasses this quota, you’ll encounter a storage error.

Large Attachments: Sending or receiving emails with large attachments can quickly consume your available storage space, especially if the attachments are not regularly deleted or archived.

Unprocessed Emails: Failure to regularly delete or archive old emails can lead to a buildup of messages in your mailbox, eventually exceeding the storage limit.

Corrupted PST or OST Files: In the case of Microsoft Outlook, a corrupted PST (Personal Storage Table) or OST (Offline Storage Table) file can cause storage-related errors, including the “Message Store Has Reached Its Maximum Size” issue.

Server-Side Restrictions: In some cases, the error may be triggered by server-side restrictions imposed by your email service provider or messaging platform.

How to Fix Outlook Fix the message store has reached its maximum size error in MS Outlook? Troubleshoot

Although MS Outlook provides inbuilt tools like an Inbox repair tool to fix Outlook errors; there are high chances that scan tool fails to resolve the Outlook error. In that case, you can also go for some other Outlook repair tool to fix the corruption in your Outlook data file. Now that we’ve identified the potential causes of the Message Store Has Reached Its Maximum Size issue, let’s explore the steps to resolve it:

Check Storage Quota: Check the storage quota allocated to your account. If you’re using an email service provider; or messaging platform log in to your account settings and review the storage limits. If you’ve exceeded the quota, consider upgrading your storage plan or deleting unnecessary emails to free up space.

Repair Outlook Data File: If the OST or PST file corruption is the issue then you can simply repair the corrupt OST file to fix the problem. For this, you can either opt for an inbuilt repair tool, or you can convert OST into PST file format to create a backup of your data file.

Delete Unnecessary Emails: Review your mailbox or message store and identify any unnecessary or obsolete emails. Delete or archive these emails to reclaim storage space. You can create folders to organize important emails and move them out of your inbox. However, the Outlook data file size will still remain large after deleting emails and to fix this, you need to compact the size of Outlook data file.

Remove Large Attachments: Identify emails with large attachments and consider removing or saving these attachments to your local storage or cloud storage service. Deleting large attachments can significantly reduce your mailbox size.

Compact PST or OST Files (Outlook): If you’re using Microsoft Outlook and a large PST or OST file is causing the issue, you can use the built-in “Compact” feature to reduce the file size. To do this, navigate to the “Account Settings” or “Data Files” section in Outlook, select the PST or OST file, and choose the option to “Compact the file” to shrink the Outlook data file size.

Consequences of Message Store has Reached its Maximum Size

Experiencing the “Message Store Has Reached Its Maximum Size” error can have several significant consequences, impacting both individual users and organizations. Some of the key consequences include:

  1. Inability to Send or Receive Emails: When the message store reaches its maximum size, users may find themselves unable to send or receive new emails. This can disrupt communication workflows, leading to missed opportunities, delayed responses, and potential frustration for both senders and recipients.
  2. Loss of Important Data: If the error prevents users from accessing their email accounts or storing new messages, there is a risk of losing important data. This could include crucial business communications, customer inquiries, project updates, or personal correspondence. Without adequate storage space, users may be forced to delete or archive existing emails, potentially losing valuable information.
  3. Decreased Productivity: The inability to manage emails effectively due to storage limitations can significantly impact productivity. Users may spend valuable time troubleshooting the error, managing mailbox size, or searching for alternative solutions. Additionally, the inability to send or receive emails in a timely manner can disrupt workflow and hinder collaboration efforts within teams or organizations.
  4. Negative Impact on Reputation: For businesses and professionals, email communication is often a critical component of building and maintaining relationships with clients, partners, and stakeholders. Experiencing issues and error can reflect poorly on the organization’s reliability and professionalism. It may create the perception of inefficiency or lack of attention to detail, potentially damaging the organization’s reputation over time.
  5. Risk of Data Corruption: In some cases, encountering storage-related errors like this may indicate underlying issues with the email client or messaging platform, such as corrupt Outlook data files. If left unresolved, these issues could escalate and lead to data corruption or loss. This poses a significant risk, especially if the affected data includes sensitive or confidential information.

Overall, the consequences of the “Message Store Has Reached Its Maximum Size” error can be far-reaching and have detrimental effects on individual users’ productivity, organizational efficiency, and reputation.


The “Message Store Has Reached Its Maximum Size” issue can be a frustrating obstacle in your day-to-day communication tasks. By understanding the causes behind this error and following the troubleshooting steps outlined in this guide, you can effectively resolve the issue and optimize your message storage for seamless communication. Remember to regularly review and manage your mailbox or message store to prevent storage-related issues in the future.

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