Be it corporate entities or business enterprises, emails tend to be one of the strongest modes of communication for conveying professional messages. However, the deep penetration of AI into our personal and professional lives, as well as highly dynamic cyberattacking tactics, have made email communications vulnerable to cyber threats. Over time, phishing and email spoofing have emerged as major roadblocks to safe and secure business talks over emails.
That’s where email authentication protocols such as SPF, DKIM, and DMARC come in. In this article, we will explore how each of these protocols works to secure and safeguard the email infrastructure of different brands and companies.
Let’s delve deeper!
What is email authentication?
Email authentication allows a domain owner to ensure that only authorized entities send emails on behalf of them or their business. It also informs the recipients if the content of the emails sent by you was tampered with in transit. This ultimately prevents targetted recipients from opening potentially fraudulent or phishing emails sent in your brand’s name
Threat actors often use email spoofing and phishing tactics to coax users into sharing their sensitive data. Email authentication technology helps detect malicious emails and prevents spammers from gaining access to your personal data.
Understanding SPF (Sender Policy Framework)
SPF or Sender Policy Framework is one of the simplest ways to prevent threat actors from sending malicious emails from your domain by impersonating you or your brand representatives. SPF requires domain owners to specify the mail servers that are allowed to send emails on their behalf.
SPF works on the basis of an SPF record. A domain owner is required to enlist all the authorized IP addresses and mail servers in their SPF record, along with ~all (softfail) or -all (hardfail) mechanism. By authorized IP addresses and mail servers, we mean the ones they trust and allow to be used for sending emails on their behalf. These could belong to their employees, third-party vendors, CXOs, etc..
Once domain owners have created an SPF record manually or using an online tool, they have to add it to their domain’s DNS for public retrieval by receivers’ mail servers.
Upon receiving an email, the recipient’s email server retrieves the SPF record corresponding to the sender’s domain and thoroughly analyzes it to verify whether or not the sending server is authorized. If the email passes the SPF check, it is placed in the recipient’s inbox. If not, it is flagged as suspicious or rejected immediately.
Limitations of the SPF protocol
- The SPF technology is not useful when an email is forwarded unless the forwarding server is listed in your domain’s SPF record.
- SPF checks only the domain in the ‘Return-Path’ or ‘Envelope From’ address (also called the ‘MAIL FROM’ address), which is used during the email’s transmission. It doesn’t check the ‘From’ part, which means that SPF cannot completely prevent spoofing.
Understanding DKIM (DomainKeys Identified Mail)
While SPF focuses on the sender, DKIM focuses on the integrity of the email content. Its job is to verify that the content has not been tampered with during transmission.
Here’s how DKIM works:
Public and private keys
DKIM functions using a pair of cryptographically secured keys. While one key is public, the other remains private. The sender’s server signs the outgoing email with the private key.
Signature in headers
Next, a DKIM signature is added to the email’s header.
Verification with public key
The recipient’s email server cross-checks the sender’s public key, which has already been uploaded to DNS records, to verify if the email contains the private key signature. In case the signature matches, DKIM protocol confirms that the email hasn’t been tampered with on its way to your recipient’s inbox.
Understanding DMARC (Domain-based Message Authentication, Reporting and Conformance)
DMARC unifies SPF and DKIM. Together, they work as a team to combat phishing and spoofing attacks. The job of the DMARC protocol is to help domain owners specify how they want the email receivers to tackle the emails that fail SPF or DKIM checks. DMARC helps in both authentication and visibility of how your domain is being used to send emails.
How does DMARC work?
Policy enforcement
DMARC requires domain owners to publish a policy in their DMARC record specifying what action to take if an email fails to cater to SPF and DKIM checks. A domain owner can specify one out of these three actions-
- None: It instructs recipients’ mailboxes to take no specific action against illegitimate emails sent from your domain. It’s done using the ‘p=none’ policy tag.
- Quarantine: Emails that fail SPF and/or DKIM checks are flagged as suspicious and placed in the ‘Spam’ folder. It’s done using the ‘p=quarantine’ policy tag.
- Reject: The emails that didn’t pass the SPF and/or DKIM checks are immediately rejected by recipients’ mailboxes. This is done using the p=reject policy tag.
Alignment check
DMARC ensures that the ‘From’ address aligns with the results of SPF or DKIM to better protect against email spoofing.
Reporting
DMARC offers elaborate reports that allow domain owners to have a close check on whether or not their emails are passing email authentication. This insight further helps domain owners take necessary actions and prevent any kind of malicious attempts.
Benefits of using SPF, DKIM, and DMARC for businesses
Improved email deliverability
Your emails safely land in your recipients’ inboxes. Email deliverability increases, thereby improving your business communication and brand campaigning. You will no longer worry about important emails landing in the recipients’ ‘Spam’ folders.
Better customer trust
Your customers and stakeholders feel secure and have complete confidence in your brand, knowing that the emails in their inboxes are legitimate and safe to open. This further enhances your brand credibility.
Minimal brand exploitation
It takes years of effort to garner a name, fame, and reputation. A cyberattack can ruin it in no time. Email authentication protocols like SPF, DKIM, and DMARC prevent your brand from getting involved in phishing and spoofing attacks, thereby safeguarding your brand identity and reputation.
Wrapping up
The combined power of SPF, DKIM, and DMARC can be used aptly to enhance email security for companies and businesses. Each protocol suitably addresses different aspects of email authentication. Together, they help strengthen your email infrastructure by keeping sophisticated email threats at bay. Organizations must integrate all three protocols to effectively protect their consumers and employees from phishing and spoofing attempts by threat actors.
While the overall email authentication process may seem complicated, the long-term benefits of leveraging SPF, DKIM, and DMARC outweigh all the challenges and make all the efforts worth it. If you are looking forward to safeguarding your email communication system, having a solid email authentication system is outright non-negotiable.
