Outlook Cache is a feature of Outlook that stores a copy of your email on your PC's local hard drive. This allows you to view your mail even when you do not have an internet connection. By default, cache is usually set to only retain a year's worth of data.
You may want to adjust this setting or turn it off entirely if you are low on disk space or need to access older emails quickly.
Alternatively, you can easily access all your email unfiltered by using the web version of Outlook: https://outlook.office.com How to adjust your cache settings in Outlook
- In Outlook, navigate to File>Account Settings>Account Settings
- In the Account Settings screen, select your InsureLine email address, then click the Change icon
- In the Exchange Account Settings screen, either disable or enable your cache and/or adjust the size of your cache by selecting the maximum age of cached mail by moving the slider
- When you are finished, click Next. On the following screen, click Done.