Les Mikesell wrote:
Comment the: FEATURE(`accept_unresolvable_domains')dnl in sendmail.mc and you won't accept email with bad reply addresses.
As an aside, the original message is legitimate. My wife and I do Alaskan malamute dog rescue. The original message had rescue related material. I suspect the reply-to email address was just wrong in the sender's email client. It is unfortunate because I am sure the people believe we have blown them off, when in reality we just can't contact them.