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Tips on managing your mailbox size

If your O365 Inbox, Sent Items, Calendars or Deleted Items folders were filled with large volume of messages over a lengthy period, you will experience performance degradation in synchronizing messages to either your Outlook client on desktop or mobile. Sizable mailbox content also runs higher risks of data corruption. Followings are few tips to assist you in managing Outlook mailbox content.

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How to check mailbox size in Outlook client
In Outlook client, choose File> Info, this information is displayed in the Mailbox Cleanup section.

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

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With the Mailbox Cleanup, you can:

  • View the total size of your mailbox and individual folders within it.
  • Find items with date earlier than a certain period or with file size larger than a certain amount.
  • View the size of your Deleted Items folder and empty your Deleted Items folder.
  • View the size of your Conflicts folder and delete items in this folder.

Try these tips for a faster, more organized approach to keep your mailbox smaller and easier to work with:

  • Archive aged items – Use Online Archive to create subfolders to hold aged messages and calendar items. You can simply drag old emails/ items from ‘Sent Items’, ‘Inbox’ or ‘Calendar’ to respective online archive subfolders created for retention purpose.
  • 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 using Teams site, OneDrive for Business, or folders on your computer.
  • Send large files by using file sharing function in OneDrive for Business instead of attaching to an email in Outlook.

Should you need further information or support in using the Online Archive service, please feel free to contact our IT HelpCentre (Tel: 2766 5900, WhatsApp/ WeChat: 6577 9669).

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