Microsoft is tightening up the security of its email offerings on Office 365 through the extension of features.

The goal here is to provide a “safer client experience” that will authenticate senders and help identify untrusted senders, helping to protect your system from spam and phishing campaigns, the tech giant explained.

While Office 365 is already pretty secure, Microsoft maintains the only way to beat hackers and other Internet nuisances is to keep one step ahead.

Phish, Spam, Spoof 

Mailboxes across Office 365 have long supported Exchange Online Protection (EOP), which filters all mail through DomainKeys Identified Mail (DKIM) over Internet Protocol version 6 (IPv6).

DKIM is a method of validating a digitally signed message that appears in the DKIM-Signature header in the messages. It ties an email message to the organization responsible for sending it. IPv6 is the latest version of the Internet Protocol (IP), the communications protocol that provides an identification and location system for computers on networks and routes traffic across the Internet.

Now, Microsoft is extending this to IPv4, the earlier IP communication protocol, effectively closing the circle against spamming and phishing.

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Security Technologies

Terry Zink is a program manager and Shobhit Sahay is a technical product manager on the Office 365 team. In an Office 365 blog post they outlined the security features that are now applied to IPv4.

Spoofing can lead to increased spam and more intensified phishing campaigns. It involves forgery of an email header so the message appears to have originated from someone or somewhere other than the actual source.

Domain-based Messaging and Reporting Compliance (DMARC) is a technology designed to combat email spoofing and is useful to stop phishing. Specifically, it protects the case where a phisher has spoofed Internet standard RFC 5322, which requires the ‘from’ field in the header of every email and is displayed in mail clients in services like Outlook and

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DMARC protects users by assessing both SPF and DKIM in emails and verifies that the mail conforms to both standards. If not, Office 365 marks the message as spam and provides better protection for users.

DKIM associates the domain a message is sent from with the message itself. The organization is a handler of the message, either as its originator or as an intermediary.

The reputation of the organization is the basis for evaluating whether to trust the message for further handling, such as delivery. It provides a method for validating a domain name identity that is associated with a message through cryptographic authentication.

DKIM allows senders to build domain reputation, which is important to ensure email delivery and provides senders a non-spoofable way to identify themselves. It is a critical component of email protection,” Zink and Sahay wrote.

While the extension of these two features will add extra protection against phishing and spam, Microsoft is not finished. It plans to add new security features to Exchange Online Protection (EOP) later in the year.