FIX: Outlook mailbox is full – cannot receive mail. (Solved) –

If you are unable to receive or send emails due to “Your mailbox is full” or “Mailbox size limit exceeded” errors in Outlook 2019, 2016, 2013, or 2010, continue reading below to resolve the issue.

Microsoft Outlook is undoubtedly the most popular email management application because it is a reliable and efficient mail application that can be used for both personal and business purposes. But sometimes there are problems that affect the performance of Outlook.

One of the most common problems is when Outlook does not receive mail in the mailbox because the mailbox is full or the mailbox size limit is exceeded. If you encounter this problem, you will find several ways to solve it in this guide.

Note: These instructions apply to Outlook 2019, 2016, 2013, and 2010 for Windows and Outlook 2019, 2016, and 2011 for Mac. You may notice slight changes.

How to fix: Outlook has exceeded the mailbox size limit or the mailbox is full.

Method 1: Clear Deleted and Junk Emails.

One way to reduce the size of your Outlook mailbox is to empty the Junk Email folder and the Deleted Items folder.

You can also get rid of deleted messages by automatically emptying the deleted messages folder when you exit Outlook. To do this, follow these steps:

1. Go to Outlook File tab and select Options.

2. Select in Outlook Options Complicated and under Start and exit Outlook options, check the box Empty the Deleted Items folder when you exit Outlook. press Ok button to apply.


3. Close and restart Outlook.

Method 2: Archive old items.

Another way to reduce the size of your Outlook mailbox is to archive old items. To do this, follow the steps below.

1. For Outlook 2016, 2019, select File tab, then select Information > Tools > Clean up the old stuff…*

*Note: In Outlook 2010, 2013, go to File > Information > Cleaning products > Archive.

Clean up old Outlook items

2. In the archive settings:

a. Choose Archive this folder and all subfolders and select the folder you want to archive. In this case, we choose Inbox.

b. under Archive items older than option, select a date.

c. Check the box Add items with the “Do not automatically archive” checkmark to archive individual folders.

d. click on OK button.

Archive settings

Method 3: Delete large emails (with attachments).

You can easily get rid of Mailbox FULL error by deleting large email files and attachments. To do this, follow the steps below.

1. press Search folders and then select New search folder.

New search folder Outlook

2. In the new search folder window:

a. Scroll down and select Big mail under Organization of mail.

b. Then, click Choose under Customize the search folder to set the mail size.

Delete large mail in Outlook

c. Specify the size display a letter larger than box (for example, “3000” KB), then click OK continue.

*Note: In this example, I specify 3000KB, which is roughly 3MB.


d. press OK once again.

3. ” a new volumegreater than xxx KB” is created under Search folders. This folder is automatically updated with messages larger than the size you specify.

4. Explore the posts in this folder and from time to time delete all junk emailsor movement the large emails under Archive folder.


Method 4: Use the Outlook Cleaner feature.

Another way to get rid of the “Mailbox is full” message in Outlook is to reduce the size of the mailbox using mailbox cleaners.

1. press File and then Information tab, click Tools -> Clearing the mailbox…

Outlook mailbox cleaning

2. In these mailbox cleanup options, you can do one of the following to reduce mailbox size:

a. select Find items older than “x” days or Find anything larger than “x” kilobytes and then to delete them. *

For example: You can find messages older than 90 days and then choose to delete them all or delete junk mail.

* Quick tip: Setting a time frame of 2-4 months is ideal. Also, the specified file size can be 2000 Kilobytes or more.

cleaning the mailbox will find old items

b. If you have defined custom archive rules in the auto archive settings (under File -> Options -> Advanced -> Auto Archive > Auto Archive Settings), click on Automatic archive button to move old items to an archive file.

c. Permanent Empty In the Deleted Items folder.

Empty Deleted Items Outlook

Method 5: Compress Outlook PST file.

1. Launch Outlook and click on it File Tab.

2. Go now Profile settings and then press Profile Settings…


3. In the Account Settings window, click Data files Tab.

4. Now if you have more than one Outlook data file (email address), select the file you want to compress and click on it Settings

Fix Outlook.  Your mailbox is full

5. click on Compact now Button to reduce the size of the Outlook data file.

Compact Outlook data file

Method 6. Increase the Outlook data file limit.

By default, Outlook Personal Data File (.pst) and Offline Outlook Data File (.ost) have a preset limit of 50 GB in Outlook 2019, 2016, 2013, and 2010, and 20 GB in Outlook 2007.

What this means in practice is that if the local Outlook data file reaches the 50 GB limit, Outlook will not be able to store new messages and will display the message “Outlook mailbox is full”. In this case, you can solve the problem by increasing the local Outlook data file size limit in the registry as described below:

1. Close Outlook.
2. It’s open Registry editor. For this:

1. Press at the same time Windows image + R buttons to open the run command window.
2. In the Run command window, enter the following: regedit and press Enter.


3. In the Registry Editor, navigate to the following location, depending on your version of Outlook:*

  • Outlook 2019, 2016: HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Outlook\PST
  • Outlook 2013: HKEY_CURRENT_USER\Software\Microsoft\Office\15.0\Outlook\PST
  • Outlook 2010: HKEY_CURRENT_USER\Software\Microsoft\Office\14.0\Outlook\PST
  • Outlook 2007: HKEY_CURRENT_USER\Software\Microsoft\Office\12.0\Outlook\PST

*Note: If “PST” does not exist under the key Outlook key, you must create it manually. For this:

a. Right click on Outlook button and select from the menu that appears: new > Key.
Name the new key: PST and press Enter.

FIX Mailbox size limit exceeded in Outlook

4a. select PST key and right click in the space on the right panel.
4b. press new > A DWORD (32-bit) value

Fix Outlook mailbox size limit exceeded

4c. Name the new value:

5. Repeat steps 4a and 4b and create a second DWORD value with the name:

6. Now double click at MaxLargeFileSize value, choice Ten and type the new file size in Megabytes (MB) in the value data. Click OK when finished. *

*Note: To calculate the new size in MB, remember that 1 GB = 1024 MB. *

For example: If you want to increase the Outlook data file size from 50 GB to 70 GB (70 x 1024), enter “71680” in the Value data field.

Increase the Outlook data file limit

7. Then double click at WarnLargeFileSize value, choice Ten and in the value data, enter the size of the new warning file in Megabytes (MB), taking into account that the size of the warning file should be 95%. MaxLargeFileSize the value shown above.

For example: If the value of MaxLargeFileSize is 71680, the value of WarnLargeFileSize should be: 71680 x 95% = “68096”

Increase the Outlook data file size limit

8. Close the registry editor.
9. Open Outlook and click Send/Receive. The problem should go away.

Method 7. Clear the Outlook cache

Outlook keeps local copies of email messages on your local computer to improve performance, and sometimes these files can cause Outlook to be unable to receive email messages. To clear the Outlook cache:

*Note: Clearing the Outlook cache does not affect your Outlook data (such as emails, contacts, etc.), and Outlook automatically recreates the cache files when you open it.

To clear the Outlook cache:

1. Close Outlook.
2. press at the same time Windows image + R buttons to open the run command window.
3. Enter the following and click OK.

  • %localappdata%\Microsoft\Outlook


4. open the RoamCache folder.


5. Select all files in this folder by clicking Ctrl + A and then press Delete press the key on your keyboard. *

*Note: Also delete these files Trash can also to save space.


6. Open Outlook.

That’s it! Which method worked for you?
Let me know if this guide helped you by leaving a comment about your experience. Please like and share this guide to help others.

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