The solutions company I work for has noticed a large increase in customer complaints regarding email spoofing and spam hitting users inboxes.
A typical scenario so far, is that someone’s legitimate email address will become spoofed and then that user will receive a large amount of NDRs. Or, spam will appear to be sent internally through fake usernames@legitimate domains.com. The spam filter is typically set to allow @legitimatedomain.com without filtering. When doing a typical analysis, we find that the messages are originating from ISPs located in Africa, Europe, and Asia.
Spoofing, and spam is nothing new, but I seriously believe that something new is on the rise that is beginning to outsmart current mail security measures. Reply back if you have noticed this also.