What's happening to my incoming email?

Since January, Cox has been warning me of the switchover to Yahoo. I finally received notice that my account was ready to switch on Apr. 7. I tried to follow the instructions but when I seemed to have done everything they required, I got a message to the effect that the system was unavailable and I should try again later.

But I had a plane to catch, so I couldn't try again later. Furthermore, I am out of the country for most of this month. Nonetheless, I notice that I am not receiving messages sent to my Cox account, even though I never successfully completed the switchover process.

I understood that nothing would change to our Cox accounts until we had succeeded in switching over. But obviously, something has changed.

What's happening to my incoming messages?