E-mails are never encrypted. The only encryption in pop3 e-mail can be in the login to the server. For webmail, it's common the mail provider uses https, but that has nothing to do with the sender.
Can you explain your complaint? What program are you using to view the mail?
Also: why should a newsletter be encrypted? It contains nothing personal, just news that is public.
emails I received lately from : CNET Deals <firstname.lastname@example.org> are now displaying a "RED LOCK" SIGNIFYING THAT THE MESSAGE SENT TO MY EMAIL ADDRESS WAS NOT ENCRYPTED.... iF I've done something .. or .. is there possibly a reason the sender is not using TLS or some type of encryption??? Respectfully Troy C.