DMARC

This is the second post in a series on DMARC.  View the whole series here.

The DMARC tag that specifies the enforcement policy is p.  This tag tells the receiver of the message what the sender would like the receiving party to do when a message fails DMARC authentication.  This policy tag has three possible values: None, Quarantine, and Reject.

• None:  The sender does not request a specific action. DMARC remains in reporting mode and continues to filter and gather data on the message stream.  

• Quarantine:  The sender asks the receiving party to treat DMARC authentication failures as suspicious.  The receiving mail server could then place the message into a spam folder, scrutinize the message with additional intensity, and/or flag the message as suspicious.  This option may provide the ability for further review by personnel tasked with analysis. 

• Reject:  The sending party asks the receiver to reject email that fails DMARC authentication.  This rejection should occur during the SMTP session, with either a full rejection and a 550 code, or a silent discard with no failure message to the sender.   

DMARC users typically start with ‘p=none’ which sets DMARC to reporting mode. After making sure their legitimate email systems pass DMARC (by either configuring their DKIM or SPF records), users typically switch directly to ‘p=reject’ which guarantees that domain spoofing emails are automatically quarantined.

DMARC is easy with Barracuda Sentinel. Visit our site here to get more information on how we can help protect you from spear phishing and cyberfraud.

Christine Barry

Christine Barry is Senior Chief Blogger and Social Media Manager at Barracuda.  In this role, she helps bring Barracuda stories to life and facilitate communication between the public and Barracuda internal teams.  Prior to joining Barracuda, Christine was a field engineer and project manager for K12 and SMB clients for over 15 years.  She holds several technology credentials, a Bachelor of Arts, and a Master of Business Administration.  She is a graduate of the University of Michigan.

Connect with Christine on Twitter or LinkedIn.

https://blog.barracuda.com

DMARC is an email authentication protocol designed to prevent domain spoofing.

Domain spoofing, where an attacker uses a company’s domain to impersonate someone in the company, is an increasingly widespread cybersecurity attack. In fact, over 96% of companies experience domain spoofing, yet only one-third of organizations use DMARC, according to the Federal Trade Commission.

[Read more…] about What is DMARC?

Asaf Cidon

Asaf Cidon is vice president of content security services at Barracuda Networks. In this role, he is one of the leaders for Barracuda Sentinel, the company's AI solution for real-time spear phishing and cyber fraud defense. Barracuda Sentinel utilizes artificial intelligence to learn the unique communications patterns inside customer organizations to identify anomalies and guard against these personalized attacks. Asaf was previously CEO and co-founder of Sookasa, a cloud storage security startup that was acquired by Barracuda. Prior to that, he completed his PhD at Stanford, where his research focused on cloud storage reliability and performance. He also worked at Google’s web search engineering team. Asaf holds a PhD and MS in Electrical Engineering from Stanford, and BSc in Computer Engineering from the Technion.

Connect with Asaf on LinkedIn.

http://www.barracuda.com