Outlook Data File Reached Maximum Size but cannot Delete! – [Solved 2026]

Is your Outlook data file reached maximum size and you are worried about it? If yes, then this is a major issue that needs a resolution instantly. The article here offers simple steps to fix Outlook data file reached maximum size but cannot delete issue. So, let’s explore the process in detail without more ado.

Microsoft Outlook is a professional email application and is widely used to handle large emails with ease. It is a platform that stores users’ data in PST file i.e. Personal Storage Table.  PST files are of two types in Outlook – ANSI & UNICODE. And whenever users send or receive emails, it preserves the copy of mail items with attached files on the system.

Thereby, size of Outlook PST files expands with time and slower the performance of the computer or Outlook application.

“The Outlook data file reached maximum size but cannot delete.”

The error means that the specified size of OST and PST have exceeded. The size limit depends on the Outlook version a user is using. So, it is essential to know that Outlook files have a specific limit for data storage.

Know Outlook Maximum Size Limit –

Outlook 97 – 2002 – predefine size limit is 2 GB

Outlook 2003 – 2007 – predefined size limit is 20 GB

Outlook 2010, 2013, 2016, 2019, and 2021 – predefined size limit is 50 GB

After understand the size limits, let us check the method to fix Outlook data file reached maximum size but cannot delete. The issue can be resolved by reducing the data stored in it, exceeding the file size limit in Outlook, removing unnecessary data files, archiving emails, and breaking PSTs into smaller parts.

So, here we’ll explain all possible ways with appropriate reasons for better understanding. And also, we will provide an alternative direct technique to fix the problem.

Outlook Data File Reached Maximum Size Limit but Cannot Delete – Why?

Before exploring the solution, it is crucial to know the main cause of problem & error. There are plentiful reasons that cause Outlook data file reached maximum size limit error. After understanding the reasons behind the issue, it will be easier to resolve it –

• Numerous emails stored in Outlook
• Large size attachments such as images, documents, etc.
• Mailboxes containing large amount of database
• Archived emails are not stored in separate PST file
• With emails, calendar entries & contacts also absorb space in Outlook
• Deleted files are still present somewhere in Outlook storage
• Outlook older version is in use
• Incorrect profile settings

Instantly Fix Outlook Data File Reached Maximum Size but Cannot Delete Error

The issue can be fixed by managing the data files on cloud and this can be done by taking help of MacMister PST Converter for Mac & Windows. With the help of the software, one can store PST files into 15+ saving types that include file formats and cloud based accounts. Its interface is friendly and easily manageable. Users with technical and non-technical skills can utilize the application without external help and resolve Outlook data file reached maximum size error with ease. With the help of the application, a user can save PST files in IMAP based server, Office 365, Google Mail, Yahoo Mail, Thunderbird and more.

Furthermore, it has been programmed with exceptional features with the help of users can implement the process as per their requirements. Also, a freeware version is available which is helpful in experiencing the entire process for free.

Manually Fix Outlook Data File Reached Maximum Size but Cannot Delete Error

Here we will explore 4 different techniques to resolve the error. We will fix the issue by deleting unnecessary files, taking help of Regedit to enhance the size limit, archiving data files, and compact them. If all mentioned methods won’t work, then opt the expert solution.

Method 1. Remove Unnecessary Data

Erasing unnecessary stored data is a simple and effective way to resolve the error. Follow the below steps to perform the same –

1. Open PST file and choose the required items which are not essential for future purpose.
2. Delete entire list of items.
3. Empty the Trash Folder/Deleted Items Folder and erase the data permanently.

Method 2. Utilize Regedit to Fix the Issue

Whenever Outlook file size limit exceeds, it will display a warning message. But you may extend the size limit manually by editing Registry entries. Go through the discussed steps to understand how to modify registry settings to enhance size of PST file –

1. Navigate towards Start button.
2. Enter Regedit in the Open box and press.
3. Now, expand the option “My Computer”.
4. Expand Software and go to Policies.
5. Now, expand:
6. 11.0 for MS Outlook 2003
7. 12.0 for MS Outlook 2007
8. 13.0 for MS Outlook 2010
9. 14.0 for MS Outlook 2013
10. 15.0 for MS Outlook 2016
11. Go to MS Outlook, select PST file and right-click on MaxLargeFileSize.
12. Afterwards, click Modify and provide value in Value data box.
13. Tap OK button.

This is a way of fixing the error “Outlook data file reached maximum size but cannot delete” error.

Method 3. Archive Outlook Data File

One can also archive Outlook data files and delete them to resolve the issue. Follow the below steps for the same –

1. Launch MS Outlook and navigate to File.
2. Tap Cleanup Tools and go to Archive.
3. Mention the date that you want to archive and tap OK.
4. Finally, selected data will be archived in a separated Archived folder.

Method 4. Compact Outlook Database

1. Run MS Outlook.
2. Go to File, click Account Settings and tap Account Settings… again.
3. Select “Compact Now” and tap OK.
4. Data will be compact and error will be resolved.

Limitations of a Manual Process

The entire methods are free to use but there are some limitations exists –

• Possibility of data loss.
• Lengthy and time-consuming.
• Need technical skills.
• It does not reduce the size limit as per requirements.

Epilogue

Facing Outlook data file reached maximum size limit error can be frustrating for many. So, to resolve the issue we have discussed instant and manual approaches. And it is advised to go for a solution that is safe and secure. As manual techniques are lengthy and require technical knowledge, thus it is advised to go for a direct method and fix the issue with ease.