4 Ways to Stop the Error Outlook Mailbox is Full After Deleting

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It is quite a common problem that Outlook users encounters often while using mailbox. Sometimes, even after deleting some data from the mailbox, it is displayed that Outlook mailbox is full.  In this article, you will know why is your mailbox says full after deleting and how to stop it from being full.

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When you delete the mails from mailbox, you certainly ensure some free space on, yet you receive the warning message stating Outlook mailbox is full. This is because, when Outlook profile is created on exchange server, a default mailbox size is allocated by the administrator. When it exceeds the size limit, you will encounter the warning Outlook mailbox is full. Sometimes, you receive warning messages after deleting some of the mails as well.

Why Is My Mailbox Still Full After Deleting?

A few reasons behind Outlook mailbox displaying full would be:

Causes for Outlook Mailbox full Solution to Fix Outlook Mailbox Full

1.       Mails that were deleted may not be taking so much space and deleting such mails doesn’t add up to storage space.


Delete Large Emails to Free Up the Mailbox Storage


2.       Trash or Delete folders not being emptied.   All the data stored in the mailbox contribute to the storage space. Therefore, deleting the mails from inbox and storing them up in delete folder or archive folder doesn’t do any good in freeing up the space.


Empty the Delete Folder

Clean up the Mailbox


3.       If you are working on OST files, it consumes large space than of PST files. In such cases, it is recommended to convert OST to PST files to free up mailbox storage space.


Convert OST to PST

If you keep facing the error after deleting the data from Outlook mailbox, try these 4 simple solutions given in the next section.

Solutions to Fix Outlook Mailbox Full After Deleting?

Here are a few methods described to resolve the issue Outlook mailbox is full. It is also recommended to take back up of your important data.

Method 1: How to Delete Large Emails to Free Up the Mailbox Storage

This is best way to delete unwanted large emails to free up the mailbox space follow the steps given below to easily resolve Outlook mailbox full after deleting or archiving.

    1. Launch Microsoft Outlook and go to Folder option>> New Search Folder option on the left corner of the tool bar.Outlook mailbox full- folder
    2. Scroll a bit down à go to Organizing mail and select Large mail. Choose the size of the file to delete under the Customize Search Folders. Click OK
      Outlook mailbox full-large mail 3.
      Emails larger than specified size will be displayed on the left side of the window.Large mail size-Outlook mailbox full

Now you can select the unimportant files and delete them in one go. What if the emails are important and you lost them? Do not worry! in such situation, you can easily recover deleted emails from Outlook.

Method 2: Empty the Delete Folder or Trash Folder

Another method to free up storage space in Outlook mailbox is to clear or empty the delete folder. When data is deleted from the mailbox, it is temporarily stored in deleted folder. Therefore, you can manage the storage space of mailbox by deleted items from the delete folder permanently.

Important Note: If you have configured the Outlook on Exchange, Outlook.com or Office 365 account, Outlook displays the Deleted Items folder. However, if you are looking for Gmail or any other email account, the folder is named Trash.

Follow the steps given below to delete items from delete folder permanently to stop Outlook mailbox getting full.

    1. Open Outlook, go to Delete Items >> Right Click and select Empty FolderDelete items-Outlook mailbox full
    2. When prompted, Confirm

You can try deleting the item permanently when you delete items from the folder. To do so, configure the settings to automate this process.

    1. Go to File >> Options >> Advanced
    2. Click on Outlook Start and Exit >> Empty the Deleted Items folder when exiting checkbox.
      Delete items automatically-Outlook mailbox is full
    3. Scroll down to others field and click the Prompt for confirmation before permanently deleting itemsPrompt the confirmation to delete items permanently

When you confirm, all the items from the delete folder deleted and create enough storage in the mailbox. Thus, the warning message Outlook mailbox is full after deleting can be fixed. If this method also didn’t help you fixing the error, you can try cleaning up the mailbox.

Method 3: Clean up the Mailbox Using Cleanup Tool

You can make use of mailbox cleanup tool to clear the older mails stored up in Outlook. Mailbox Cleanup option verifies the size of mailbox size and filters the older emails than a specific date. Also it can find emails based on size of Archive mail items, view Deleted Items folder size, and empty or delete Deleted Items and Junk folders. Follow the steps below to use Mailbox Cleanup:

    1. Navigate to File >> Tools >> select Mailbox CleanupMailbox Cleanup-Outlook Mailbox Full
    2. You can select emails to clean based either on the days or the size of the files. Once you provide the specification, click on Find Select the messages to delete from the list and clear the Mailbox.
      Clean up tool to fix mailbox full error
    3. You can also make use of AutoArchive option to move old emails to an archive (.pst) automatically. This can free up the mailbox storage and fix the error message.

Method 4: Convert OST to PST

If you are working on offline or using the default Cached Exchange Mode, you can convert OST to PST or split oversized OST file to small PST based files to manage space on mailbox. By converting OST to PST, you not only free up the mailbox storage space but also reduce the corruption in OST files. It also makes access of the mailboxes easy.

When OST file is converted to PST file, the attachments are linked dynamically where users can access the attachments directly from the email without any hassle.

Steps to convert OST to PST using SFWare

Download and Install SFWare OST to PST conversion software on your computer. Launch the application.

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    1. On Main screen- Two options Open OST file and Find OST file are displayed

Open OST file: select this option to repair inaccessible, corrupt or damaged Outlook OST file.

Find OST file: select this option when you’re not aware of the OST file location. The tool will automatically find the OST file

Find OST file to convert

    1. Click on Browse to store the converted OST fileConverting OST file
    2. The software will start the conversion and will generate a healthy PST file which is ready to use.

Now, you will have a large OST converted to PST file that contains all your Outlook items that were saved in an OST file. By importing this PST file into your Outlook, you can successfully access all Outlook attributes.


When Outlook Mailbox is full, you will not be able to send or receive any mails. To stop this from happening, make sure to keep your mailbox storage space free. If you still encounter the warning message mailbox full after deleting everything, follow the methods explained in the article and fix the error.

Frequently Asked Questions:

Why does Outlook keep saying my mailbox is full?

A few reasons behind Outlook displaying mailbox full are undeleted old mails that is consuming space from mailbox storage, working in offline mode and also due to corruption in Outlook data files.  Sometimes even after deleting or arching the mails, you end up encountering the warning message. This is because deleted or archived messages will be still be existing on the storage space which makes mailbox storage full.

Do deleted emails take up space in Outlook?

Yes, deleted emails if not permanently deleted from the mailbox take up space in Outlook. You can easily free up the space by emptying the delete or archiving folder as described in the write-up.

How do I stop my Outlook mailbox from being full?

You can stop Outlook mailbox full warning message by deleting the large size mails or old emails that are unimportant. Emptying the archive folder or delete folder also helps in fixing the problem. If you are working on OST, thee best option is to convert OST to PST. By converting you can fix any Ost/ PST corruption and OST large file size issues.

Does converting OST to PST reduce Outlook mailbox space?

Yes, absolutely. As mentioned in the article, When OST is converted to PST large OST files can be converted t small files and hence occupies less space in mailbox. It is also easy to access PST files from anywhere anytime without any hassle. Also, PST files are the most reliable file format and corruption/ damage to PST files can easily be repaired compared to OST.


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