Prevent Outlook to download external contents.To resolve this issue, use one of the following methods:

Step 3 - Check the problem caused by external content Let the task in process finish its job before you try another action. If you try to perform other actions while Outlook is in use, Outlook may not respond. If Outlook is in use by another process, this information is displayed in the status bar at the bottom of the screen. This is because these processes can use a large number of resources. Performance may be decreased if you use the Outlook AutoArchive feature or sync to Outlook with a mobile device. Step 2 - Make sure that Outlook is not in use by another process For more information, see How to install the latest applicable updates for Microsoft Outlook (US English only). Make sure that the latest updates for Outlook are installed. Install Windows updates in Windows Vista.To install the latest Office updates, click the link for your version of Windows, and then follow the steps in the article:

By installing important, recommended, and optional updates, you can often correct problems by replacing out-of-date files and fixing vulnerabilities.

This might be because Windows Update is not configured on your computer to automatically download and install recommended updates. The Office installation on your computer might not be up to date. These steps are provided in a specific order based on commonality and complexity.

Outlook 2019 hangs on loading profile