What To Do When Outlook Mailbox Is Full And Cluttered?

  

Rollins Duke   
Published: August 26th, 2025 • 12 Min Read

Suddenly attacked by the “Outlook Mailbox is Full” message alerts and missing emails because of it? No need to worry, because this article covers what to do when Outlook mailbox is full and everything the user needs to fix it quickly and permanently. Stay till the end to discover the reasons, what happens when the Outlook mailbox is full after deleting, guaranteed fixes, and many more alternative solutions to solve the problem quickly and permanently.

Think of losing access to important emails or missing a business opportunity because users’ Outlook Archive Mailbox is almost full. Let’s make sure that never happens again.

Why Is Outlook Saying My Storage Is Full?

Before we learn what does it mean when Outlook says your mailbox is full message and what to do when Outlook mailbox is full but it’s not, it is first important to understand the Outlook mailbox storage limit. Outlook storage typically refers to the maximum amount of storage taken up by user’s Outlook account, including emails, attachments, calendar entries, and other items. Once the user crosses this limit, their Outlook stops receiving or sending emails and shows the “Outlook mailbox full error” or “Quota Exceeded”. So, there are several reasons why Outlook says the mailbox is full and some of the most common explanations for receiving Outlook mailbox full delete everything notifications are as follows:

• Exceeding the Maximum Size Limit: Outlook imposes a maximum size limit of 2 GB to 50 GB as per Outlook edition for users. Once this limit is surpassed, users won’t be able to send or receive emails, and Outlook starts saying the mailbox is full. Even a large PST file crashes Outlook when users try to start it.
• Cache and Junk Files: Besides important data, users’ Outlook mailbox may contain cached or junk files. These files can make some of their data unreadable or invisible, then Outlook says storage is full.
• Third-Party Plug-ins: While third-party tools can be beneficial if they are secure, some may have logical issues that can affect Outlook’s storage. Choosing reliable third-party add-ins is crucial.
• Attachment Size: If the user frequently sends and receives emails with large-size attachments, then it consumes significant storage space, and see Microsoft Outlook full storage notification.
• Sync Issues: Due to improper synchronization settings, Outlook might start downloading duplicate emails. Therefore, it is essential to make sure users are using the correct sync settings and then follow the guidance to remove duplicate emails in Outlook PST file.

What to Do When Outlook Says Mailbox is Full?

Any idea what to do when outlook says mailbox is full can’t send messages? Several issues may arise, affecting user’s productivity and data. Read the below-mentioned bulletins to get a glimpse of the results:

• Decreased Performance and Possible Hangs: The overall performance of Outlook may decline, and the application may hang or freeze at times.
• Increased Risk of Data Corruption: If the mailbox exceeds its size limit, there is a higher chance of users’ important PST file or data getting corrupted.
• Potential Data Loss: Outlook email storage full error can lead to data loss, making it vital to address this issue promptly.
• Outlook Not Sending/Receiving Emails Due to Full Mailbox: When users’ Outlook storage is full, they won’t be able to send or receive email messages.
• Error Notifications: Microsoft email full storage notification starts alerting the user that their mailbox is over its limit.

What To Do When Outlook Mailbox Is Full – Manual Methods

#1 Fix Outlook Storage Full Error Deleting Large Items

It is very obvious that the large attachments or files downloaded in our Outlook account consume a lot of space. Therefore, to make some storage, deleting the large and unnecessary files is a great idea. Hence, to know what to do when Outlook says mailbox is full, follow these steps:

1. Firstly, open MS Outlook on your computer.
2. Next, go to the “Search Folders“.
   
3. Click on “New Search Folder“.
   
4. Scroll down and select the “Large Mail” option from organizing mail.
   
5. Click on “Choose” and specify the size larger than the desired limit (XYZ KB) to delete.
   
6. Enter Mail Size to show mail greater than the specified size and press “OK“.
   
7. Finally, open those folders and delete unnecessary large items.
   

#2 Free Up Space on Outlook Using Compact Option

Using the compact option to resolve the query of “what does it mean when outlook says your mailbox is full” is a great idea. Thus, it eliminates the unused as well as storage holding space that is present in Outlook and declutters the platform.

1. Go to “Account Settings” in the “File” tab.
   
2. See configured email accounts and navigate to the “Data Files” tab.
   
3. Select the Outlook Data File you wish to compress and click on “Settings“.
   
4. Now choose the “Compact now” option to resolve the Outlook storage full error.
   
5. The compacting process has been initiated, please wait until completion.
   

Note: Even after deleting unnecessary data or compressing large PST files, the error may persist due to mailbox corruption. Oversized PST files often lead to crashes and database corruption. If the above-mentioned techniques fail to resolve Outlook mailbox storage full, then go with the upcoming solution.

#3 Empty Folder Option to Clear Outlook Storage

Another manual method helps with mass storage clearing and gives ample space for further mail saving. Therefore, the steps to use this tool are as follows:

1. Launch MS Outlook on your computer.
2. Choose the Delete Items/Junk Email folder accordingly.
3. Right-click on the selected folder and choose “Empty Folder“.
4. All items in the selective folder will be permanently deleted, click “Yes” to continue.
   

#4 Archive the Old Outlook Mails

If the user has lots and lots of old Outlook emails that they don’t find important at present but may need them in the future then archiving them is the best option. It not only move them to another folder but will also free up some space in the mailbox.

1. If you are using Outlook 2016, click on Files.
2. Now, go to “Info” and choose “Tools“.
3. Next, click on “Clean up old items”.
4. Further, select the option “Archive this folder and all sub-folders”.
5. Click on all the labels that you want to archive.
6. Once done, type a date range under the section “Archive items older than” so that only those emails that fall under that range get archived.
7. Next, click on “Include items with Do Not Auto Archive”.
8. Lastly, tap on the “OK” button and you are done freeing up Outlook space.

#5 Use Outlook Email Clean-Up Tool

If the Outlook mailbox full after archiving, then use this dedicated email cleaning tool that is by default present in Outlook. There are various options to clean up Outlook mailbox and free up space and declutter the platform by eliminating unnecessary emails. The steps to use this method are as follows:

1. Firstly, start the Outlook and click on “File”.
2. Now, go to “Info” and choose “Cleanup Tools”.
3. Next, select “Mailbox Cleanup”.
4. Further, you get various cleaning options such as “Find items larger than“, “empty deleted items”, “view conflict size”, “view deleted item size”, and so on.
5. Choose any of the options and perform the operation required to free up Outlook storage.

Drawbacks of Using the Manual Method

There are multiple conventional ways to resolve the query “what happens when outlook mailbox is full”. However, each of them has some shortcomings which create inconveniences for the users like splitting the same file twice which users can rectify by using the Outlook Duplicate Remover. Understand more reasons why manual methods are not used to clean up Outlook storage:

• Traditional techniques require technical knowledge to complete the process effortlessly.
• The risk of losing the data is always present while using manual ways.
• They are not effective enough in compressing the emails to provide storage space.
• Manual methods are not suitable for Outlook corrupted files.
• They are very time-consuming to perform.
• Users may still face the issue Outlook mailbox full after deleting everything.
• Due to the standardized process, users might make errors while operating though manual techniques.
• Users cannot reply completely as these methods are only suitable for temporary fixes.
• Does not help in compacting the size of the file, making such methods inefficient and ineffective.
• Organic techniques do not guarantee of preserving the integrity of the data information.

How to Free Up Outlook Space With Expert Solution?

Unlike manual methods, the above-mentioned tried and tested software makes PST splitting and freeing up the Outlook space easier, safer, and quicker than ever. Thus, the steps to use this recommended tool are as follows:

1. Download and install the software on your computer.
2. The software will automatically detect your Outlook profile or allow you to select files manually.
   
3. Choose the recovery mode if any corrupted files are detected.
   
4. Select the required folders from the software window and press “Next“.
   
5. Browse to the destination path to store resultant files.
   
6. Navigate to the split options and select “Split by size“.
   
7. Click on “Split” to start the process.
   

Note: Once the user saves the Outlook PST file to the desired location, it’s completely their choice to either keep it as a backup or import it in Outlook again. In both ways, user can clean up their Outlook mailbox. 

Benefits of Using Expert Solution

• It automatically fetches the Outlook profile details and configures seamlessly.
• Has a recovery mode to deal with corrupted and lost PST files.
• Represent labels and sub-labels in a hierarchy for easy selection.
• Gives various splitting options such as “Split by size”, “Split by date”, etc.
• Allows browsing the destination to save the resultant or split PST file.
• The robust tool provide users numerous options to divide their files accordingly by date, size, sender and receiver details.
• The tool loads more quickly and is less likely to occur any crash or hand.
• Users can include their Outlook files without worrying about the size of the files as this modern tool does not impose any size limitations.

To Conclude

So, are you ready to reclaim your Outlook space and never face this issue again? Try the manual ways to simply use the expert’s recommended tool to see the instant results. Don’t let Outlook full mailbox hinder productivity or slow down the computer when the user can fix it in minutes. In the above guide, we solved the most asked query which is “What to do when Outlook mailbox is full”.

So running out of mailbox space in Outlook can be frustrating, hindering your ability to communicate effectively. By following the methods outlined in this article, users can successfully resolve the issue as we have discussed what to do when the Outlook mailbox is full and what happens when the Outlook mailbox is full.

It is crucial to remember that manually deleting unnecessary data and compressing PST files may not always be sufficient. In such cases, a reliable professional’s trusted tool offers a comprehensive solution. With its user-friendly interface and efficient splitting capabilities, users can easily increase Outlook mailbox size. Don’t let an over mailbox limit the productivity and communication—take action today to keep the Outlook experience seamless and hassle-free.