The last two are definitely not from eBay or PayPal, the first one looks ok, I've had messages from ended@ebay.com, old ones from when eBay VERO'd some of my items listed on .com, perhaps they use caended for Canadian listings.
As to what to do......how about just ignoring them (except for the caended one if you had a listing pulled by eBay).

"What else could I do? I had no trade so I became a peddler" - Lazarus Greenberg 1915
- answering Trolls is voluntary, my policy is not to participate.