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Summary: Outlook on the Web users can streamline email management by manually deleting older emails from specific folders or creating auto-deletion rules. These rules work across all mailbox messages, efficiently removing unnecessary emails. For Outlook desktop applications, the Mailbox Cleanup wizard helps manage mailbox size. Adopting practices like archiving, emptying deleted items, and storing attachments externally can maintain a responsive Office 365 mailbox. A backup solution, such as Kernel Office 365 Backup & Restore, is also recommended for data security and streamlined email management.

A business email account accumulates a substantial daily influx of emails, some of which are only relevant temporarily and can be purged later. Outlook on the Web, the web-based iteration of Outlook, offers sophisticated tools for efficiently deleting older emails.

Delete older emails from individual folders

Within your mailbox, various folders house emails categorized by type. Inbox holds new messages, Sent items store outgoing emails, Drafts house unfinished compositions, Junk mail houses undesirable emails, and Archive is reserved for older correspondence. To remove older emails from these folders, utilize Outlook settings within Outlook on the Web.

  1. First, log in to Outlook Web App and click on ‘View all outlook settings.’View all outlook settings
  2. In the General category, go to the Storage option.go to the Storage
  3. The list will show various folders and their sizes. You can open the Empty dropdown and select one among the various options- ‘3 months and older,’ 6 months and older,’ and ’12 months and older.’show various folders and their sizes

Outlook will promptly eliminate emails in accordance with your chosen criteria. While this manual method efficiently discards older items, it necessitates separate actions for each folder. Regrettably, there are no additional filtering options available in this process.

Create an auto-deletion rule for the mailbox

To simplify the challenges of manual selection and deletion, consider crafting a rule applicable to all mailbox messages. When you’re confident that emails past a certain date are no longer needed, implementing a rule can efficiently delete them and free up storage for future use.

  1. In the Mail category, go to Rules.go to Rules
  2. As you haven’t created any rule, click the Add new rule option.
  3. Type a new name for the rule. It will be good if the name is meaningful. Apply the condition for deleting the name for the rule
  4. In Add an action dropdown list, choose Delete as the desired action.Add an action
  5. Click the checkbox to Run the rule now and click the Save the Save button
  6. The new rule is active and will start to work on all folders present in the account’s rule is active and will start to work

Now, older emails will no longer consume unnecessary storage. If you know about the retention policies in Office 365, then they are suitable for accidental deleted items. But the above-created rule will be helpful in removing unwanted data completely.

Delete older emails from Outlook 2019/2016

The Outlook desktop application operates within a Windows environment, handling your Office 365 mailbox and email communication. As the mailbox size grows, it can lead to slower performance and account opening delays. Fortunately, there are effective features and techniques available to easily remove older emails and enhance overall performance.

  1. First, click the File option and go to the Tools category. Open the list and select Mailbox the File
  2. The Mailbox Cleanup wizard has various settings to Empty, Delete, and AutoArchive emails from the selected account.selected account

Administrators can leverage this functionality when the mailbox surpasses its maximum storage capacity on an email server like Exchange. You have the flexibility to configure values according to specific requirements.

You must try the following practices to keep your mailbox lighter and more responsive and there will be no requirement to find for old emails in Office 365 anymore.

  • Archive older items – Move older emails to an archive folder. In this, a different Outlook Data File (.pst) is created, which you can access from Outlook whenever you need it. Also, you can set Outlook to automatically archive items on a regular basis. Whenever you choose, you can manually archive stuff as well. You can choose which items to archive, when to archive them, and where to keep them.
  • Empty the Deleted Items folder – If you want to make sure you aren’t keeping messages you don’t need, regularly empty the Deleted Items folder.
  • Empty the Junk Email Folder – Clear the Junk Email folder on a regular basis to make room in your mailbox.
  • Store attachments outside your mailbox – Attachments can use a large amount of space as they grow over time. Consider saving attachments to a team site, OneDrive, or a folder on your computer.


Taking a backup of your Office 365 mailbox is a prudent step to safeguard against data loss from various potential risks. Additionally, you can efficiently declutter your mailbox by removing unnecessary emails. The Kernel Office 365 Backup & Restore tool is an ideal solution for preserving Office 365 data in offline files accessible across multiple platforms. It offers extensive filtering options for selecting essential mailbox items.