I've got weird things going on with my Apple mail (which I use across a Mac, iPhone and iPad). I'm seeing things I've never looked at already appearing 'read'. It doesn't seem to be a sorting issue (apple intelligence driven 'priority messages' etc),
Change your password and restart all your devices.
I know nothing of Apple, but that sounds like you've left something open somewhere that you've forgotten about, or an app playing silly buggers maybe. Forcibly terminating extant connections should sort it out I think.
Using the Mail app on a Mac rebuild the mailbox(es) first (select Mailbox in menubar and Rebuild is the last option). Occassionally my machines show messages that I can't delete as they're all ready gone from one of the other devices
I second trying a rebuild.
Deleted my gmail account from my phone/iPad/iMac and added it again with the default settings. Still happening. Odd
Did you rebuild the mailbox on your Mac? Do that first.
Did you rebuild the mailbox on your Mac? Do that first.
deleting the account on the Mac did that - rebuild is the same thing but without reentering my login details. It spent hours redownloading all the messages. it's only rebuilding the local database as well.
Actually I'm pretty sure it's NOT a Mac issue Im pretty certain it's happening when I've not had the Mac mail app running on the desktop (I turned the iMac off when I was away for a few days at Christmas and was still seeing stuff already read on my phone.
There's something wrong with the interface between Mac Mail and Outlook/Hotmail too. Many instances of having to login again on phones and iPads here. I'm not a Google user so unable to determine if it's a cross-provider problem. Exchange at work doesn't suffer the same problems.