How to Clean up Outlook Mailbox?

Last Updated on June 27, 2022 by Amit Bansal

mailbox cleanup button

Have you ever thought about cleaning up your inbox? Or did you ever try to clean out your email account, only to realize a month later that you didn’t delete anything? Well, don’t worry because I got you covered. In this article, I will show you ‘How to clean up your Outlook mailbox.’

Did you know that almost 50% of emails get deleted or misfiled every day? This means that if you want to stay organized, you should take time to clean up your email accounts. If you aren’t deleting old messages, then they are piling up and taking over your inbox.

Many people waste a lot of their time sorting through old emails. They simply let them clutter up their inbox until it becomes overwhelming. When that happens, they start to get stressed out and frustrated. The solution is simple – organize your email into folders.

Let’s check out the pathway:

Open Outlook, click on the File tab, open the tool >> and click Mailbox Cleanup.

mailbox cleanup

View Mailbox Size

If you want to free up space, you should be able to view your inbox, see who sent you messages, and delete those that you no longer read.

You might be thinking viewing your Outlook mailbox size would be quite impossible, Outlook allows you to dig deeper and will allow you to view the size of your Inbox.

To find out, you’ll need to go to the Mailbox cleanup dialog box appears >> View mailbox Size.

A separate Folder Size window appears, which reveals the size of each folder. By default, it opens up in the Local Data tab. Local data is the data that is stored on your computer in your .pst and .ost files.

View Mailbox Size outlook

The columns show the names of the folders, their sizes, and their combined size if they contain sub-folders. The best thing about this view is that it lets you see hidden folders like the Calendar. If you’ve got numerous years’ worth of appointments and meeting requests, you can quickly free up space by deleting old events.

All the above numbers (data) appear in kilobytes, you can analyze them by converting the figures into Megabytes

Apart from this, you can also check out the server data by clicking on the ‘Server Data‘ tab. When you open a new Outlook window the first time, it may take a minute or two to load. This happens because Outlook is making sure the data is up-to-date on your files. After the initial update, there should be no delay when opening any new tabs.

outlook check mailbox size

When you open a new Outlook window the first time, it may take a minute or two to load. This happens because Outlook is making sure the data is up-to-date on your files. After the initial update, there should be no delay when opening any new tabs.

By default, Outlook only keeps emails from the past year on your computer. This means that old emails stored on your PC are downloaded from an online server. Email accounts are usually set to ‘Download messages’ or ‘Always download’, but you can change these settings.

How to Find Large and Old Emails?

The best way to lighten your email is to find large segment emails or older ones, which are further not required in your inbox or any other folder.

You can work across your entire email folders, to find out related emails or get the results in a few clicks.

How to Find Large and Old Emails

You can want to find emails with large attachments, you can automate the size using the manual option, and enter the size (for instance if you want to find all mails over 10 MB, you need to change the ‘Find items larger than’ field to 10000 kb.)

On the other hand, you can also find emails older than the days specified in “find items older then”.

Then click Find.

The resulting panel appears you can further modify the search using (Look for, messages, more choice, Advanced).

Find Large and Old Emails

From the search results, you should be able to open each email and delete it or remove attachments. You should be able to save the attachments before doing either.

Auto archive

The auto-archive is a smart method to remove unwanted emails from your folder, something we have already covered, simply click on the ‘AutoArchive‘ button from mailbox cleanup.

Auto archive

This process searches through every folder in your Outlook inbox and does automatically archives messages. You have no control over what happens here.

You can set up a rule to auto archive emails in our folder, which will be removed automatically when the time hits the parameter.

View deleted item Size

Deleted any email message only shift your email into a deleted folder, it doesn’t mean that message remove permanently. Here is the option under mail cleanup.

Click ‘View Deleted Items Size’ to check out the size of the folder and how much space your deleted items are taking up, Click ‘Empty’ to delete the folder entirely.

Empty under mailbox cleanup

View Conflicts Size or Delete

Lastly, in the mailbox cleanup delete conflict messages, These are emails that Outlook thinks conflict with an existing email because they have the same header information.

These are alternate versions of items in your mailbox, to check this out, click the view Conflicts Size button to see a filtered version of the Folder Size.

view conflicts size


That way you can determine the size of your mailbox and take action accordingly. By removing emails on a regular interval you will get rid of alerts warning that your mailbox is getting. The above options and proper action prevent your Outlook mailbox from getting full.

Amit Bansal

Hello, my name is Amit Kumar Bansal, and I am the founder of Through this blog, I focus on Microsoft Outlook, offering insightful and informative content. Additionally, I produce educational videos on YouTube to further enhance the understanding of my audience. visit my YouTube Channel

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