Outlook slow updating cached messages
Here are a few things you can do to keep PST files from growing: Solution #2: Disable Add-ins that are not in use Running unnecessary add-ins may make Outlook slower. You probably have more add-ins installed than you think.Check what Add-ins you have installed and disable the ones you are not using.It is suggested to fix the issue by compacting the Outlook data file using Compact Now option, or use a reliable PST repair tool.Solution #4: Enable Cached Exchange Mode If you are using an Exchange-based mail account, enabling Cached Exchange Mode will likely improve Outlook responsiveness.Solution #7: Disable RSS feeds in Outlook However, you can see how overall client user experience can be affected by these performance issues.
Outlook periodically updates the local file, adding new messages and archiving older ones.
For Outlook 2016, Outlook 2013 and Outlook 2010, 100,000 items per folder and total 500 folders.
For Outlook 2007, you can have maximum 50,000 items per folder and 500 folders total. Well, there are a few simple steps you can take to improve Microsoft Outlook performance.
These files are known as cached files and can be safely deleted.
Clear the Outlook cache if old data remains after you delete it, something that may happen when you remove and reinstall Outlook add-ins.