closing one window closes all windows

[ndb]

When I try to close an individual email message, my entire email browser will
close along with any other windows that were opened within that email
browser. This holds for any email account that I may use on my personal
computer. They are not opening as tabs in one window. Once it has all
closed, an "blank" window shows briefly before closing and an error message
is sent to microsoft.

How do I stop this?

thanks

 

[PA Bear [MS MVP]]

IE version?

What's an "email browser"?

What anti-virus application or security suite is installed? What
anti-spyware applications (other than Defender)? What third-party firewall
(if any)?