It seems that
Shunn.net and the usually ultra-reliable
Pair.com (my Web host) are completely inaccessible this morning. Wondering if it was just a local DNS problem, I VNC'd to my work machine and tried from there. No go. No word on how long the outage will last, since of course I can't get to Pair.com for email or news on the subject. I'm hoping it's just a bad DNS table at some important node between here and there and not something more serious.
Update: We're back. If you sent email in the last hour or so, it might not have gone through.