Safe mode is not an external application, but it is a separate mode in which Outlook works with some restrictions.
The seasoned Outlook users know about the safe mode because various Microsoft products use the safe mode to operate the software in a limited manner. The safe mode is also present within the Outlook settings and there are various methods. If you are also facing the same error or any other error, then you can try to open the Outlook in safe mode. A general error message while opening the Outlook is ‘ Cannot start Microsoft Outlook. But sometimes, when Outlook is facing any challenge due to any problem whether it is hardware, software, networking, etc. The majority of the times, MS Outlook opens easily in the computer and the user can access the respective account.