I’m seeing scattered reports today that a lot of places are seeing backed up queues to Yahoo. They’ve had some problems over the last few days and seem to be still recovering. It’s looking like it’s something internal to Yahoo. One set of error messages I’ve seen reported by numerous people is: “451
4.3.2 Internal error reading data.”
It’s not you, and it’s not spam related. But it is putting a crimp in a lot of companies attempts to send lots of email ahead of black friday and cyber monday.