Mac Mail Query

[Tykebike]

Hello everyone,
This is my first post here on MacRumours and I'm looking for a bit of help.
I've had a MBP since 2015 and am fairly conversant with using the Mail app but since buying a M2 Mac mini from the Apple Refurbished store here in the UK nI've noticed that, from time to time, there are multiple identical windows shown in the windows drop down menu. Today it had 3 copies of the inbox listed; I'm not sure if it could be any other mail folder as it's only been the Inbox so far.
Does anyone have any suggestions please?

 

[adrianlondon]

Close them all apart from one, then restart Mail.

Windows still there? You could try deleting the prefs file(s) in ~/Library/Containers/Mail. I have a few of them, which is weird, all just called "Mail". I once deleted them all (after copying them somewhere just in case) and it sorted a mail issue I was having with no side effects.

Windows still there? Boot into "safe mode" then reboot normally. That deletes quite a few caches.

Windows still there? No idea.