Microsoft today announced that Office 365 now supports inbound validation of DomainKeys Identified Mail (DKIM) over IPv4, and Domain-based Messaging and Reporting Compliance (DMARC). These techniques check for trusted authenticated senders and help identify untrusted ones that that fail authentication. Exchange Online Protection filters every single mailbox on Office 365 already had this Inbound DKIM for IPV6.
Spoofing is a raising challenge for enterprises causing increased spam and more intensified phishing campaigns. With these added functionalities feature, Office 365 users can expect better brand protection and an even safer experience.
Read more about it here.