Do you know that something as convenient as email can knock down a billion-dollar company to the ground?

Yahoo, the IT behemoth, was enjoying its glorious heydays till a tragedy struck them that changed the course of the company’s future. In August 2013, the internet giant became a victim of a highly malicious email hack that compromised 1 billion accounts. Immediately after the breach, the company sent a mail to its users to change their passwords and terminated the security questions and answers. However, on 12th September 2016, just three years after the hack, Yahoo rounded up the actual number to 3 billion. That’s equivalent to the combined population of India and China!

This announcement came at a time when the web giant was in the midst of an important billion-dollar acquisition Verizon deal. What happened to Yahoo after this hack was nothing short of a nightmare. It lost a whopping $350 million from the deal and was fined $80 million for non-disclosure of data breaches. Little did they know that a single spear phishing mail would script their meteoric downfall!

This 9-year-old data breach has become a distant memory for a lot of people. Yet its impact is still felt strongly in the internet and technology landscape. However, this raises a fundamental question: Has email security fared for better or for worse?

Let’s find out!

Present Email Security Landscape: The Scenario Still Looks Grim

The truth is that nothing much has changed when it comes to email security. In fact, there has been a stupendous rise in the number of email breaches over the last two years. Here are some alarming statistics that sum up the current status of email security:

  1. 83% of organizations faced email data breaches
  2. 59% of IT leaders cited a rise in email data leaks due to remote working
  3. 24% of email data breach incidents were caused by human error
  4. 42% of IT leaders expressed that half of all breaches would go undetected

What’s causing the rise in email security threats? The answer: Legacy email systems.

Legacy Email Infrastructure: The Achilles Heel

Did you know, that an employee, on an average, receives 120 emails each day? If an organization has 200 employees, its email security solution scans 24,000 emails per day. Generally, email scanning is done on-prem. Now imagine if there is an DDoS attack on the IT network. Is the legacy email security solution capable of protecting the emails from such a cyberattacks? The answer is no.

Legacy email systems are built with rudimentary defense features that cannot counter sophisticated cyber-attacks. Their siloed approach limits them from identifying and assessing newly advanced threats. But this is just tip of the iceberg. Integrating advanced email security tools for Data Loss Protection (DLP), web security and end point security into the legacy system can cost a lot. On top of that, they cannot secure extremely confidential data. Due to this, the company has to face the brunt of compliance and regulatory fines. Legacy email security solutions cannot detect east-west email traffic between employees. Their detection approach lacks the ability to analyze signals based on user’s identity and behavior, including what device they have used, sign-on location and authentication method. Most of them fail to track suspicious behavior like impossible travel, new devices and authentication methods in case of compromised email accounts.

Re-defining Email Security on the Cloud

A study by Gartner shows that the highest consumed cloud-based security service is email security as 74% of businesses found legacy email security solutions to be ineffective.

An Email Security Gateway comes with four authentication protocols namely SPF, DKIM, DMARC and BIMI to prevent phishing and spoofing. Let us understand these authentication techniques in detail.

Sender Policy Framework (SPF)

Sender Policy Framework is a DNS TXT record that assesses email domains and checks if they are from a valid IP address or not. It maintains an SPF record of the IP addresses of credible senders. When the servers receive messages, they validate the SPF by examining the return-path value present in the header’s email. The recipient server uses the return path value to verify the TXT record on the sender’s DNS server. It scans the list of approved IP addresses that are permitted to send emails against the domain used in the return-path address. If the sender’s IP address is present in the list, the mail clears the SPF authentication check. Otherwise, the SPF check fails. Since the inbox gets flooded with spams everyday, SPF checks filters them out from the relevant email addresses. However, remember that SPF is used to verify the sender’s address and not their identity.

Domain Keys Identified Mail (DKIM)

DKMI verifies if the content of the email has been modified in transit. It uses an encrypted digital signature in the mail’s header to let the receiver know if the mail is from an authorized domain. If you want to implement DKIM, you need to add a DKIM record to the DNS. A DKIM record contains a public key that the receiving servers use to authenticate the DKIM signature. Once the receiver gets the mail, it decrypts the signature and verifies it with the public DKIM key on DNS. If the signature matches, then the DKIM is valid.

Domain-based Message Authentication, Reporting, and Conformance (DMARC)

Along with deploying SPF and DKIM, DMARC adds another important function to email security: real-time reporting. It allows you to publish policies and reports which contains information to prevent unauthorized emails and share insights about email channel and sender’s identity. Generally, there are two kinds of DMARC reports:

  • a) Aggregate (RUA): It provides thorough information about a particular domain’s traffic and usage. Details like domain name, IP addresses, frequency of emails, timeframe are chalked out in RUA. However, RUA does not give you an overview of the contents of the email. These reports are sent to domain owners who take decisions on how to enhance email security.
  • b) Forensic (RUF): Unlike RUA reports, RUF reports give you an in-depth insight into the email content including the header, subject line, receiving and sending email address. RUA Forensic reports are sent out if a particular email on your domain fails to qualify for both SPF and DKIM checks.

Brand Indicators for Message Identification (BIMI)

BIMI is a new kid on the block. Though it is similar to SPF and DKIM, there is one key difference. While SPF and DKIM check the authenticity of the mail directly from incoming mail servers, BIMI evaluates the mail’s credibility in the inbox. If you get a mail from a brand, it usually has a logo. But if the mail does not contain any logo or other brand attributes, BIMI registers the mail as spam or rejects it.

Detection and Prevention Of Threats via Email


Sandboxing is used to identify new threats that do not show any suspicious behavior in virtual environments. They are also known as zero-hour or zero-day threats. The sandbox leverages a legion of advanced technologies such as machine learning (ML), signature checking, static-code analysis, heuristic and other behavioral analytics. These tools are used to analyze the code and patterns for suspicious behavior in the mails. The sandbox runs hyperlinks and files in an isolated, virtual environment that mirrors the computer system. If there is any sign of malicious activity, the link will get instantly blocked. It also helps them to identify advanced threats that utilize anti-evasive techniques which normally would go unnoticed. Remember, that sandbox doesn’t reject the mail outright. Instead, it quarantines messages. This is because there is a possibility of false positives where authentic mails can be identified as harmful. These kinds of mails are kept in a quarantine folder and are manually checked by the security team.

Behavior analysis

AI-powered behavior analysis blocks hidden email threats by examining email attributes like delivery behavior, attachments and social engineering tricks in real-time. It checks if an email has reused malicious code to block ransomware variants. At the same time, it deploys file decomposition tools to identify hidden ransomware in email attachments.

Malware and Spam Protection

You cannot stop spam mails but you can definitely avoid them. Enabling malware and spam protection helps you to investigate high-risk links and attachments with technologies such as reputation analysis, antispam filters, antispam engines and antivirus engines.

Isolating and Containing High-risk Threats

Threat isolation acts as a strong deterrent to high-end and innovative email hacks such as spear phishing and credential theft. It creates an insulated execution environment where it shows the inoculated web content to the users. While it isolates suspicious links remotely and scans them for any further malware. As a result, any threats posed by these risky files are simply neutralized.

Encouraging Proactive Threat Response

By leveraging analytics, you gain insights into harmful emails and indicators of compromised mail. You can integrate analytics into the Security Operations Center (SOC) and Security Information and Event Management Systems (SIEM). You can quickly scan through the threat landscape and gauge the threat’s nature, scope and severity. Here are three ways in which enabling quick threat response can vet out email threats:

  1. Speed up your attack response
  2. Scan instantaneously for threats across internal and external environments
  3. Remediate threats to engineer an immediate response

Preventing Data Loss

If your security posture is strong, your ROI will high. This is why it’s essential to enhance your security stack with advanced email security features like DLP and encryption controls, network, endpoint and cloud security. DLP and encryption controls stop data leakage and help your organization adhere to latest compliance measures and policies. A DLP policy can identify risky mails against a pre-determined list of keyword dictionaries and Multi-purpose Internet Mail Extensions (MIME) lists. On the other hand, the policy-based encryption feature encrypts a highly-sensitive mail as a password-protected PDF. Some email security solution providers also help you customize encryption requirements.

Other benefits of a cloud email security solution provider are:

  1. ML-enabled spam filtering to block spam mail every month
  2. Domain intelligence to maintain domain reputation and deliverability
  3. Automate the IOC blocklist for identifying emerging threats

Cloud4C: All-in-one Managed Cloud Solution for your Email Security Woes

Email is an inevitable tool for vital business communication. Today more than ever, businesses need to protect against email-borne attack vectors. While sound email services have in-built security, businesses may need more advanced features just like Cloud4C’s email security services.

Cloud4C, one of the world’s largest Cloud MSPs and a cybersecurity solutions leader with advanced MDR, EDR, Managed SOC, Threat Intelligence, SIEM-SOAR offerings, extends an on-demand, advanced threat protection framework with email security best practices. We provide comprehensive email security solutions and services to help businesses protect their email, and confidential data. These services are backed by cutting-edge technologies and a cumulative approach to restrict advanced threats while staying compliant. Know more about our advanced, cloud-powered email security services. Get in touch to enhance your email security today!

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Team Cloud4C
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Team Cloud4C

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