I recently moved from Plusnet to EE (which I understand is a sister company in the Plusnet/BT family).
I had a conversation with support before the account was due to switch, as I wanted to know how to retain our email addresses. I was assured that we would switch to a "mail only" account, that I didn't have to do anything else, that you would monitor for the closure and ensure that we kept access to all of our email accounts, and would let us know when it was all done.
The switch over happened in the early hours of this morning. Our emails seemed to keep coming through this morning, so all seemed well, but by this evening we had started receiving bouncebacks and messages saying emails couldn't be sent. Tonight everything seems to have gone.
These are our only email addresses and used by our whole family. We are waiting for confirmation of my mum's vaccination for Covid and have access to nothing at the moment.