How to use mailbox cleanup to purge your outlook folders of rubbish

The more email you send and receive, the larger your Outlook mailbox can grow. Large mailboxes can take longer to open and search, and many email providers, including Microsoft 365, limit the maximum size of your mailbox. If you receive a message that your mailbox is over its size limit, deleting messages and folders can help, but if you store your information in an Outlook Data File (.pst) or Offline Outlook Data File (.ost), that data file may not shrink in size automatically.

Note: If you use a POP account, all of your email account information, including your folders, email messages, contacts, calendar, and task information is stored in an Outlook Data File (.pst). If you use an Microsoft 365, Exchange, IMAP, or Outlook.com account, a copy of your mailbox is stored in an Offline Outlook Data File (.ost).

To reduce the size of your Outlook Data File (.pst) or Offline Outlook Data File (.ost), you can manually compact the data file. Select your version of Outlook below to see instructions on how to reduce the size of a .pst or .ost file.

There are several ways to reduce your mailbox size.

You can use the Mailbox Cleanup tool to view the size of your mailbox and individual folders. This tool can also help you search for older or very large messages that you might want to delete or move to an Outlook Data File (.pst).

Often, the cause of a large mailbox is a large Deleted Items folder. The tool provides a button to view the size of your Deleted Items folder and empty your Deleted Items folder.

Occasionally, Outlook will store conflicted items in a folder called Conflicts. Conflicts happen when a copy of an item stored on your email server is out of sync with a copy of an item stored on your local computer. The Mailbox Cleanup tool can delete these conflicts for you.

Run the Mailbox Cleanup tool

Click the File tab.

Click Tools > Mailbox Cleanup.

Select View Mailbox Size, Find items older than, Find items larger than, View Deleted Items Size, Empty Deleted Items folder, View Conflicts Size, or Empty Conflicts to perform your desired task.

Use Conversation Clean Up to remove redundant messages

In a long email thread, there are often numerous messages that contain all of the same information as prior messages. Conversation Clean Up can remove those redundant messages automatically. For more information, see Use Conversation Clean Up to delete redundant messages.

Search for large messages

You can search for all messages larger than a specific size from Outlook’s Search box. Click in the Search box and type: messagesize:>5 mb. This will find all messages larger than 5 MB. You can delete some or all of these messages or move them to another Outlook Data File (.pst). For more information on moving items, see Move or copy a message between folders.

If you delete items from an Outlook Data File (.pst) or Offline Outlook Data File (.ost), Outlook automatically compacts the file in the background during idle time, when you’re not using your computer, but Outlook is still running.

Note: Outlook only compacts the file if there is more than 20% of ‘white space’ (unused space) in the file.

You can also use the following steps to manually start the compact process immediately, which may take several minutes to complete.

Delete any items that you do not want to keep and empty the Deleted Items folder.

Click File > Account Settings > Account Settings.

On the Data Files tab, click the data file that you want to compact, and then click Settings.

Note: If you are using an Exchange or Outlook.com email account, you need to additionally click the Advanced tab > Outlook Data File Settings.

In the Outlook Data File dialog, click Compact Now and then click OK.

Note: You do not have to exit Outlook after you compact an Outlook Data File.

Are you getting weekly or even daily messages warning that you’re about to run out of mailbox space? Mailbox Cleanup is a one-stop-clean-up tool you can use to trim the size of your mailbox.

In Outlook, choose File> Tools > Mailbox Cleanup.

Do any of the following:

View the total size of your mailbox and of individual folders within it.

Find items older than a certain date or larger than a certain size.

Archive items by using AutoArchive.

View the size of your Deleted Items folder and empty your Deleted Items folder.

View the size of your Conflicts folder and delete this folder.

Best practices to keep your mailbox lean

If your email is stored on an email server such as Exchange, when your mailbox reaches its upper limit your administrator might start limiting functionality. For example, at 90 MB you might get a warning, at 100 MB you might be unable to send email, and at 110 MB you might be unable to receive email.

Here are some ways to keep your mailbox size under control:

Archive older items – Move old items you want to keep to an archive. You can create a separate Outlook Data File (.pst) that you can open from Outlook any time you need it. By default, Outlook automatically archives items at a regular interval. You can also archive items manually whenever you want. That way, you can decide which items to archive, when to archive them, and where to store them.

Note: If you don’t see the Archive command, your organization may have turned off the feature.

Empty the Deleted Items folder – Empty the Deleted Items folder frequently to make sure you aren’t keeping messages you don’t need.

Empty the Junk Email folder – Periodically empty the Junk Email folder to save your inbox space for messages you actually want.

Store attachments outside your mailbox – As attachments accumulate over time, they can take up a lot of space. For attachments you want to keep, consider saving them to a team site, to OneDrive, or to folders on your computer.

In Outlook, choose File> Cleanup Tools > Mailbox Cleanup.

Do any of the following:

View the total size of your mailbox and of individual folders within it.

Find items older than a certain date or larger than a certain size.

Archive items by using AutoArchive.

View the size of your Deleted Items folder and empty your Deleted Items folder.

View the size of your Conflicts folder and delete this folder.

Best practices to keep your mailbox lean

If your email is stored on an email server such as Exchange, when your mailbox reaches its upper limit your administrator might start limiting functionality. For example, at 90 MB you might get a warning, at 100 MB you might be unable to send email, and at 110 MB you might be unable to receive email.

Here are some ways to keep your mailbox size under control:

Archive older items – Move old items you want to keep to an archive. You can create a separate Outlook Data File (.pst) that you can open from Outlook any time you need it. By default, Outlook automatically archives items at a regular interval. You can also archive items manually whenever you want. That way, you can decide which items to archive, when to archive them, and where to store them.

Note: If you don’t see the Archive command, your organization may have turned off the feature.

Empty the Deleted Items folder – Empty the Deleted Items folder frequently to make sure you aren’t keeping messages you don’t need.

Empty the Junk Email folder – Periodically empty the Junk Email folder to save your inbox space for messages you actually want.

Store attachments outside your mailbox – As attachments accumulate over time, they can take up a lot of space. For attachments you want to keep, consider saving them to a team site, to OneDrive, or to folders on your computer.

Is your mailbox full? Are you getting weekly or even daily messages from your system administrator saying you need to reduce the Microsoft Outlook mailbox size? This can lead to a lot of wasted time cleaning up your mailbox. Try these tips for a faster, more organized approach to keep your mailbox smaller and easier to work with.

Note: With the move in many organizations from Exchange Server (local/network) to Exchange Online (cloud/Office 365), the following steps will be less important as storage space is dramatically increased. However, it’s still a best practice to reduce the number of items in Outlook for simpler organization and faster search. And, you can still cleanup your Outlook mailbox size if you are running Outlook as a stand-alone (POP3) version. Reducing the size often improves performance.

Caution: Before starting these steps, take the time to backup your Outlook.pst file (stand-alone version) which is usually found under the Outlook Files folder in Documents.

The following steps apply to Microsoft Outlook 2016, Outlook 2013 and Outlook 2010:

1. Mailbox Cleanup

The best place to start is to open the Mailbox Cleanup tool. In Outlook, choose File > Info > Cleanup Tools > Mailbox Cleanup.

1. First, choose the View Mailbox Size option which scans the size of your mailbox and all of the subfolders. This is a great way to target which folders are the biggest contributors to your large mailbox so you can clean these up first.
   When connecting to Exchange, you’ll see a Local Data and Server Data tab. Only look at the Local Data tab; cleanup changes you make will automatically take place on the server as well.
2. Next, pick the options to Find older or larger items which you can delete directly from the results to cleanup the Outlook mailbox size.
3. Depending on your archive settings (see Archive Older Messages below), you can also run an AutoArchive.
4. Finally, check the size of the Deleted Items folder and Empty the folder if you want (specific options detailed below as well). If available, one option is to view and delete multiple versions of items in our mailbox.

2. Move Messages to Your Personal Folders

If you’re accessing Outlook from Exchange, another way to reduce the Outlook mailbox size is to move Outlook items to your Personal Folders. This option may not be available to you as many organizations have moved away from supporting Personal Folders.

Even though the messages you move to Personal Folders are no longer counted in the size of your mailbox, the Personal Folders file (outlook.pst) is stored on your local hard drive and is not accessible remotely. You should also backup this file to prevent losing these Outlook items if your computer goes down or is updated. If you are running a standalone version of Outlook your email, calendar, tasks, and notes are all stored in the outlook.pst file (or .ost file-offline) which has a size limit of 50GB (Outlook 2019, 2016, 2013 & 2010).

3. Archive Older Messages

Another useful maintenance step is to periodically archive your Outlook folders. If you are accessing Outlook from Exchange, you may not be able to change archive options as archiving is often controlled by system administrators or a third party program.

Setup your archive preferences under the Info > Cleanup Tools > Archive option. The archive.pst file can be created and updated at any location you specify, usually your local hard drive. Archived items are removed from your Outlook mailbox size and moved to the archive file based on the settings you determine. Just as with the Personal Folders file, your archived items are not accessible remotely; the file should be backed up on a regular basis.

4. Empty Deleted Items

Quickly clean up your deleted items by automatically emptying the Deleted Items folder when you exit Outlook. To apply this option choose File > Options > Advanced tab. From the Outlook start and exit option, check Empty Deleted Items folder when exiting Outlook and OK to apply.

To manually clear deleted items, locate and right-click the Deleted Items folder and click Empty Folder on the shortcut menu (Empty “Deleted Items” Folder for Outlook 2010). Once you clear deleted items, it cannot be reversed. If you feel confident that you want to delete a message forever, you can bypass the Deleted Items folder by pressing [Shift] + [Delete] for a selected item instead of pressing the [Delete] key. Then confirm the delete process.

5. Save and Remove Attachments

Attachments in email messages are responsible for a bulk of the space used in your Outlook mailbox. Depending on the email communication, one option is to save the attachment and then to remove the attachment from the original message. This requires extra steps yet may help slim down the size of your Outlook mailbox:

1. Open the message.
2. Right-click on the attachment and then pick Save All Attachments. Or select Actions from the Message tab. Then pick Other Actions > Save All Attachments.
3. Next, locate and select the folder where you want to save the file(s) and pick Save.
4. Once you have saved the attachment, delete the message if it doesn’t need to be retained. If you need to keep the message, you can remove attachments from a message by right-clicking them and choosing Remove.

Bonus: Reduce the Size of an Outlook Data File (.pst)

Note: This tip only applies to Outlook running on a stand-alone computer.
If you delete items from an Outlook Data File (.pst), the file is automatically compacted in the background when you’re not using your computer and Outlook is running. You can also manually start the compact command immediately. It will likely take several minutes to compact an Outlook Data File (.pst).

1. Following the steps above, delete any items that you do not want to keep and empty the Deleted Items folder.
2. Click the File tab.
3. Click Account Settings, and then click Account Settings.
4. On the Data Files tab, click the data file that you want to compact, and then click Settings.
5. Click Compact Now.

NOTE: You do not have to exit Outlook after you compact an Outlook Data File (.pst) file.

Start applying these mailbox clean up actions to grab greater control over your Outlook mailbox size.

For more time saving Microsoft Outlook techniques, find additional shortcuts, tips and tricks at

By Dawn Bjork, MCT, MOSM, The Software Pro®
Microsoft Certified Trainer, Productivity Speaker, Software Consultant

I am using outlook.live.com on my MacBook and the only thing I want to do is either Archive my folders/email files or make space in my Outlook account to send and receive emails without deleting my email messages. A .PST export will work as well.

If you have the key to this process, I would very much like to know so I can unlock the code.

Report abuse

Replies (6) 

Hi Valkeever,
You can log into Outlook.com and archive your mailbox to a pst file but should first empty the deleted items and clear out as much just as you can.

Open Outlook.com’s settings: Settings (gear icon) > View all Outlook settings > General > Privacy and Data to request a pst archive.

But you should try to get it underquota because mail flow will not restart until you are under quota and it can take 24 to create the pst archive.

1. Empty the recovery folder linked at the top of the Deleted items folder. (The recovery folder has a different, smaller quota, but emptying it can help speed up the processes.)
2. Sort the deleted items folder by size and delete the largest messages – select the first, scroll down and hold Shift as you select another message. Then hit Delete.
3. Empty the recovery folder again.
Repeat the steps.

Diane Poremsky [Outlook MVP]
Outlook Resources:

** I don’t work for Microsoft.**
** DO NOT CALL phone numbers received in email notifications.**

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Microsoft Announces Office 2019

Understanding G Suite Licensing

The Useful Clean Up Mailbox Option Hidden in OWA

Even with Massive Mailboxes, Some Run Out

Even with 100 GB mailbox quotas, some people do run out of space and need more to keep receiving new mail. There is no way to increase an Exchange Online mailbox quota past 100 GB, so if someone like this comes calling, you can recommend them to move a pile of email into an expandable archive or empty their Deleted Items folder to free space. Later, when the panic has abated, you might consider applying a retention policy to the mailbox to keep it under some sort of control.

A New Option

Or you can tell the user to fire up OWA and select some folders for cleaning with the very useful “Clean up mailbox” feature buried in OWA. Go to Options (cogwheel), select Mail, and voilà (Figure 1)! A link to Clean up mailbox also appears under mailbox usage in the General section of options.

Figure 1: OWA Options reveals “Clean up mailbox” (image credit: Tony Redmond)

The feature appeared without warning. At least, no one from Microsoft said anything about it at the recent Ignite conference, I can find no documentation online, and it is not listed in the Office 365 Roadmap. The feature is unique to OWA and does not appear in Outlook desktop or the mobile clients. It’s a mystery, albeit a nice surprise.

Cleaning Up

Before you can do anything, OWA enumerates the folders in your mailbox and calculates how much space each folder occupies, with Deleted Items and Junk Email at the top of the list. You can get a similar view with PowerShell:

The difference is that OWA excludes many of the utility folders found in user mailboxes (like the Audits folder) and only lists those that hold user data. To decide how best to free up space, you select individual folders and then look at the clean-up options proposed by OWA. For instance, in Figure 2 we see that my Inbox occupies 1.26 GB for 6,959 messages. Cleaning out messages older than 12 months will remove 3,583 items. While OWA does not tell you this, it is reasonable to assume this will reclaim at least 0.5 GB.

Figure 2: Deciding how much email to remove (image credit: Tony Redmond)

Before OWA removes anything, you must confirm that the operation should proceed (Figure 3).

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Figure 3: The warning about permanent removal (image credit: Tony Redmond)

Recoverable Items

Permanent removal means that the items do not go into the Deleted Items folder. Instead, they go into the Deletions sub-folder under Recoverable Items and stay there for between 14 and 30 days, depending on the deleted items retention period configured for the mailbox. During this period, you can recover messages using the Recover Deleted Items feature available in OWA or Outlook.

Once the retention period elapses, the messages are irrecoverable because Microsoft does not take backups for Exchange Online. Given the sheer number of mailbox databases running inside Exchange Online, it is unreasonable to expect Microsoft to take traditional backups. This has always been the case and if you are uncomfortable with this situation, you can put mailboxes on hold to force Exchange to keep the data. Users will not be able to recover messages after the retention period elapses, but administrators can run content searches to find and recover items if necessary.

Alternatively, you can investigate cloud-based backups for Exchange. Before you do, read this article and review the comments in the Microsoft Technology Community.

Cleaning is Good

Even if you are not under pressure to free space in your mailbox, it is still a good idea to have a regular clean-out. Few messages need to be kept for extended periods and if items are needed for compliance purposes, they are probably on hold (or should be).

The problem with features buried deep in a list of options is that most users never find them. Who has the patience or the time to investigate every setting in OWA Options? I don’t. But I was glad that I found this one.

Want to know more about how to manage Office 365? Find what you need to know in “Office 365 for IT Pros”, the most comprehensive eBook covering all aspects of Office 365. Available in PDF and EPUB formats (suitable for iBooks) or for Amazon Kindle.

Learn how to clean up your Outlook 2013 mailbox for better performance and to ensure you do not exceed your allocated server space.

Auto Archiving

• AutoArchive will move messages over 6 months old from your mailbox hosted on the Exchange server to a mailbox on your local computer. Please keep in mind archived messages will not be viewable through Outlook Web Access because they are no longer stored on the Exchange server.

Setting up AutoArchiving

• In the main Outlook 2013 window, click on the File tab and click on the Options button. The Outlook Options dialog box will appear.
• Click on the Advanced button in the Navigation pane on the left. The options for working with Outlook will be displayed.
• In the AutoArchive section, click on the AutoArchive Settings button. The AutoArchive dialog box will appear.

Note:

If you turn on AutoArchive without changing any of the other AutoArchive settings, Outlook automatically archives items every 14 days, sending items that are over six months old to the archive file listed in the AutoArchive dialog box. For most people, those settings are just fine. Some users prefer to turn off the AutoArchive feature and run the archive process manually, these instructions are shown below. You can turn on or off the AutoArchive process by selecting or deselecting the Run AutoArchive Every check box at the top of the AutoArchive dialog box. You can also change how often AutoArchive runs by replacing the 14 in the text box with any number between 1 and 60.

If you filter your mail into multiple folders, you may want to set different AutoArchive schedules for each mail folder. To do this, right click on the email folder, select Properties, and select the AutoArchive tab. Select “Archive this folder using these settings.” After you have made the appropriate changes, click “OK” to save the changes.

Mon 21st February 2011

I do admit that I am a bit of a hoarder. Money off coupons, business cards, lovely samples of quality paper products – anything that looks like it might be of use in the next 15 years finds a home in my office. The trouble is my office is in my home; and my home office drives the rest of the family nuts. My husband has long since given up calling my workplace the office and now refers to it as “The Victorian Emporium”. I must admit my surroundings do have more than a slight resemblance to the Olde Curiosity Shoppe.

But when it comes to my desktop – that’s a different kettle of fish. There’s nothing more irritating to me than hoarding and saving messages in my Microsoft Outlook mailbox. Here, money off, special offers and unimportant emails don’t stand a chance. If, like me, you use Outlook 2003 then there are various quick and simple ways to keep your mailbox free of clutter.

Obviously every time you delete an email message, the message moves into the Deleted Items folder. But in order to avoid an overstuffed bin, you need to keep cleaning it out. Since the messages have made their way into your Deleted Items, you are probably sure that deleting them permanently will not cause any catastrophe. So to make things easier, you can specify when and how you want your Deleted Items folder tidied up: you can tidy up automatically every time you quit Outlook, or do it manually whenever you like.

If you are sure that you need never access your Deleted Items, simply use the Empty the Deleted Items folder when exiting setting to automatically delete messages. To set this up, click Options on the Tools menu and click the Other tab. Or simply right-click Deleted Items and select the Empty “Deleted Items” Folder command on the shortcut menu. It’s a bit like putting the rubbish out every night and not just on bin day. However if you prefer, you can empty the Deleted Items folder manually with a simple right-click, or you can use the Mailbox Cleanup dialog box.

Now I love to hoard junk mail that falls on my doormat, so when it comes to email attachments, I have to be really disciplined. Sometimes I do need to keep email attachments, but this doesn’t mean cluttering up my In box with original messages. Attachments can take up a lot of space, so if you don’t need to store them in your mailbox, don’t.

Instead, use the Save Attachment command on the File menu and save the attachments to another location on your hard disk. Once you’ve saved the attachment, you can delete the message, or you can right-click the attachment icon and select Remove to keep the message but remove the attachment. Make sure you are really organised, and that you have a location on your hard disk to save your attachment to. Also, when you save the attachment, give it a name that will help you remember its contents and context. To save attachments to a location outside your mailbox, use the Save Attachments command on the File menu. This command is available when you have an email message open.

And it’s not just your In box that needs an occasional spring clean. Remember to have a good look through your Sent Items for anything that can be deleted or refiled to save on space. You don’t have to keep messages in your Sent Items box to keep track of what you have sent and to whom. It’s a good idea to try to archive the Sent Items folder regularly. To specify archive settings for AutoArchive, right-click the Sent Items folder, click Properties, and select the AutoArchive tab. If you prefer to archive manually, click Archive on the File menu, and scroll to select the Sent Items folder.

And remember, don’t respond to unsolicited email messages, junk messages or chain letters; and never click links within this type of email that encourage you to “Click here to remove yourself from this mailing list”. By responding to these “remove me” links, you’re letting the sender know that there’s someone at home at your email address, and you’re likely to encourage more of this type of junk email. There’s enough of that sort of rubbish piling up in my in tray to sift through – never mind my Outlook folders. Obviously Outlook has a number of reliable tools that you can easily apply to help you to avoid junk email and other unsolicited mail shots.

Outlook comes with lots of command line switches and parameters which can be very handy for troubleshooting and (limited) automation.

This guide contains an overview of all available command line switches per Outlook version and how they can be used.

Using command line switches

You can directly execute command line switches in the following way:

1. Open the Run command by pressing the Windows Logo + R on your keyboard.
   Alternative ways are:
   • Windows 7
     Open the Start Menu and use the Search field to type in for the next step.
   • Windows 8
     Open the Start Screen and directly start typing. This will automatically open the Search Pane which also allows for commands.
   • Windows 10
     Type in the Search field (Cortana) or open the Start Menu and directly start typing. This will automatically open the Search Pane which also allows for commands.
2. In the box you opened in step 1, type; outlook.exe
3. Press the SPACEBAR once, and then type a forward slash mark ( / ) followed by the switch you want to use (see the list below). For example, if you want to use the CleanReminders switch, the command you type in the Open box should look like this:
   outlook.exe /cleanreminders
4. To run the command, click OK or press ENTER.

Starting Outlook with the cleanreminders switch in Windows 7.
(note the space in the command above).

Starting Outlook with the cleanreminders switch in Windows 10.

Tool Tip 1
To have easy access to all the “direct start” command line switches (the switches that do not require further variables), you can use HowTo-Outlook’s very own OutlookTools (free).

Tool Tip 2
Need more Outlook management options via the command line? ReliefJet Essentials Pro provides batch script and PowerShell support for over 150 of its utilities related to configuring, reporting, converting and exporting Outlook data.

Creating custom shortcuts with command line switches

You can also create a shortcut which includes one or more switches so you can automate tasks or start Outlook in a certain folder like the Calendar;

1. Search for the location of outlook.exe :
   • Windows 7
     Open the Start Menu and in the Search field type: outlook.exe
   • Windows 8 and Windows 10
     Open the Start Screen and directly type: outlook.exe
   • All Windows versions
     You can also browse to the path of outlook.exe .
     Examples:
     • Outlook 2010 on a 32-bit version of Windows
       C:\Program Files\Microsoft Office\Office14\Outlook.exe
     • Outlook 2013 32-bit on a 64-bit version of Windows
       C:\Program Files (x86)\Microsoft Office\Office15\Outlook.exe
     • Outlook of Office 365 on any version of Windows C:\Program Files\Microsoft Office\root\office16\Outlook.exe
2. Right-click on Outlook.exe, and then on the shortcut menu point to Send To, and then click Desktop (create shortcut).
   • Windows 8 and Windows 10
     Right click on the outlook.exe search result and choose “Open File Location”. This will open a new Explorer window with outlook.exe highlighted. Right click on this file and choose: Send To-> Desktop (create shortcut).
3. Go to the Desktop (keyboard shortcut Windows+D).
4. Right-click the shortcut you just created, and from the shortcut menu click Properties.
5. On the Shortcut tab, locate the Target box. It contains the path for outlook.exe .
6. Press the SPACEBAR once to type a space after the path, and then type;
   /select outlook:calendar
   The full command should now look like this;
   “C:\Program Files\Microsoft Office\root\office16\Outlook.exe” /select outlook:calendar
7. Click OK.
8. On the desktop, double-click the Outlook shortcut you created.

Creating a custom shortcut with the command line to start
Outlook in the Calendar folder (click on the image to enlarge).

Tip 1!
To create a shortcut that creates a new message, follow the above instructions but instead of typing /select outlook:calendar use /c ipm.note .

Tip 2!
You can also create a Send To shortcut for Outlook which has the /a switch. This allows you to select files in Explorer and use the Send To-> Mail Recipient feature to create a new message with the selected files as attachments while also adding your signature and not blocking Outlook. For details see: Send To Mail Recipient in HTML and with Signature.

Command line switches overview

The overview of commands below are taken from various local and on-line help files of all Outlook versions and from KB articles discussing them. In the right column you’ll find to which Outlook version the command applies.

• Upgrades colored For Follow Up flags to Office Outlook 2007 color categories.
• Upgrades calendar labels to Office Outlook 2007 color categories.
• Adds all categories used on non-mail items into the Master Category List.

Note: This is the same command as Upgrade to Color Categories in each Outlook mailbox properties dialog box.

Problem

When your mailbox reaches 100 GB in size, you are no longer able to send mail. To prevent this from happening, you will want to reduce the size of your email box.

Error message

In Outlook, the user receives the following error message:

The message store has reached its maximum size. To reduce the amount of data in this message store, select some items that you no longer need, permanently (Shift + Del) delete them.

In Outlook Web App, the user receives the following error message:

The action couldn’t be completed. An error occurred on the server.

Solution

What solutions you might take will depend upon how close to the limit you are. You’ll need to use a combination of Outlook Web App and the Outlook Client.

Figure out your mailbox size

1. Open Outlook and select the File tab
2. With the Info section selected you will find the size under Mailbox Settings
   

Get rid of RSS feeds

It’s a good idea to get rid of your RSS feeds. RSS feeds were part of the original upgrade to Outlook from GroupWise, and at one time were useful. Today, though, they just take up a lot of mailbox space, so if you have them, you should delete them. Since they can be quite large, it’s easier to do this through the Microsoft 365 Outlook WebApp, rather than through Outlook on your desktop, since the Web App doesn’t have to synchronize the changes.

1. Expand RSS Feeds
2. For each of the RSS Feeds (Microsoft at Home, Microsoft at Work, MSNBC News, Popular Government Questions from USA.gov and USA.gov Updates: News and Features), right-click the folder and choose Delete.
3. Click OK to the Delete Folder confirmation dialog box.
4. Once you’ve deleted all of the RSS Feeds, empty your Deleted Items folder.

Unsubscribe from email you don’t need

We all get email sent to us every day from websites or mailing lists we’ve signed up for. It’s a great way to get reminders or alerts about things we’re interested in. It’s also a great way to increase our mailbox size if we’re not vigilant about deleting them when we’re done! Unsubscribing from mailing lists that you no longer need means less email coming in, and a smaller mailbox.

Delete what you don’t need to keep

This is pretty straightforward. Select the mail or mail folders you want to remove, and then right-click and choose Delete. Don’t forget to empty your Deleted Items Folder when you’re done. Some places you might want to look for mail you can purge:

• Drafts – get rid of any drafts you don’t need or never sent.
• Sent items
• Conversation History
• Junk E-Mail (you can right-click and Empty this folder)
• Reminders
• Restored Items

Focus especially on large items. You can check your folder sizes by opening Outlook on your Windows computer.

1. Right-click the root of your mailbox (your name).
2. Click Folder Size.

You can see the size of any subfolder and use that to determine where to focus the most time and effort.

Use Sort to find large emails too, especially the “Size” and “Attachments” sort options.

Remove attachments from an email and keep the email

Emails with attachments create large emails that take up a large chunk of your mailbox space. Rather than saving those attachments that are emailed to you, save them to your network drives and then remove them from the email.

1. Right-click the attachment and choose Save As or Save All Attachments to save the file to a folder on your computer or on your network drive (like P or O).
2. Then right-click the attachment and choose Remove Attachment.
   
3. You’ll retain the email message, but the attachment (which you saved elsewhere) will be removed, reducing your mailbox size.