FOr years when I delete mail on my Mac (all my email accounts are shown in Apple Mail) it deletes those same emails on my iPad and on my iPhone. But in the past week or so, even after deleting on my Mac, the emails are showing up on my iPad and I have to go through & then delete each of them again.
I don't usually check emails on my phone, but every day I am now getting a message on my phone that I have to enter the password for my Apple account. I would expect this is related somehow? Of course, going into settings it is not accepting the PW that works on my computer. But that may be because it doesn't like my finger writing - I don't see a keyboard to use. (eg zero vs letter O)
So something weird is going on.