When I ‘fixed’ some DKIM issues a couple of days ago, I used the same file name for two different functions accidentally and this broke the configuration in ways that affected mail lists. That has been corrected.
In addition, I misconfigured the client mail server in a way that permitted open relaying and that got abused this afternoon about the same time a customers account had been compromised and also abused. And so around 1:30PM today Pacific Time I had to stop the client outgoing server for a short while in order to fix the configuration error and delete 40,000+ spam messages from queue. Fortunately I caught the majority of them before they were sent.