Note that this posting has a normal subject, i.e. "Re: Unidentified subject!"
If it does not appear thus, then the problem is somewhere in lists.debian.org. Almost all, but not all, messages recently have subject like Unidentified subject! [ ] in the topics list and Unidentified subect! () in the "Encapsulated message." (I believe that more than the usually shown headers appear at the end of the message body.) This is very annoying and without topics, the digest in nigh impossible to use!