Why is my Outlook closing when I am simply closing a mail message

[WendyG]

After I have read an email in Outlook and click on the "close" symbol on the
top right-hand of the screen, instead of simply closing the email message it
is closing Outlook completely.
This has only just started happening and does not happen every time, but
fairly frequently (and annoyingly).
Can anyone help please.
Thanks
WendyG

 

[Pat Willener]

Does this also happen when you use Ctrl+F4 to close the message?

If not, then I suspect that your mouse may be doing this. I just had to
replace my mouse because every single-click resulted in a double-click.