One is presently away from the home router and, of course, good old (free) hotmail has decided again to need authorisation as 'you appear to be using a different location etc etc…' and like the OP my alternate address is sadly another hotmail address which (surprise, surprise) is also unavailable due to the security concerns….
Maybe the gods are telling me to leave the comfort of Microsoft's offerings and to go forth. It's very frustrating.
SHJ