Dear All,

Some users are experiencing mailbox space issues in Outlook; please do the following to resolve this issue: 

                   HOW TO SOLVE MAILBOX SPACE ISSUE

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.

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.

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.