Can't Delete An E-mail Folder

This is Microsoft Office 2019 Outlook on a Windows 10 PC. I have a folder where the option to close it is greyed out:



It is not any of my e-mail accounts and I've been able to delete other folders, but this one is stuck. I just want to get rid of the whole item. Any advice? Thanks.

 

If the folder you want to delete lives in your computer, you could boot into the Safe mode and delete it from there.

If it lives outside of your computer, then I can't help you 'cause I don't know the details concerning your setup.