Hacked! Spam! How in the heck . . . ?
So when my GMail account got hacked, and I became an unwilling spambot . . . the spammers appear to have sent spam to every email I have ever used. That includes an email account with Blogspot that enables me to post by email. (Which, admittedly, I haven't done in a long time.) That explains the spam post, which I am now going to try to delete.
Update: Spam post deleted.