I hate the JetPack upgrade.
It made everything stop working.
No emails going out.
No posting to social media sites.
I guess this problem has been going on for the past four days or more. I hate it when things that work without issue break. Their support forum has at least 8 posts in it over the past 24hrs of people asking what the hell is up with the upgrade. I just tried to fix it. We shall see if it works. I disconnected JetPack from my site – then reconnected it again.