Partly off topic but still related to Teams and Outlook. Most probably any of recent Teams update caused the issue that I couldn't re-open, delete or rename *.msg files. I found a fix at https://learn.microsoft.com/en-us/a...t-open-msg-file-(error-we-cant-open-msg-its-p (2nd answer) In my case Teams COM add-on was to blame, disabling it resolved the issue. JFI in case someone is experiencing the same problem.
