I posed the same question at rec.radio.flamefest, I mean shortwave, and
someone there recommended that I post the link to the Radio World email
signup. So here it is:

http://www.rwonline.com/dailynews/signup.shtml

Anyone who wants the digest directly in their inbox can sign up for it at
that link. That way, you'll have it even if I forget to post it here. My
memory is pretty weak sometimes.