Welcome to Part 6 of our definitive domain cybersecurity checklist! Today, we’re focusing on securing email servers, a critical component of your domain’s cybersecurity strategy. With expert insights from EBRAND’s CTO Anouar Adlani, we’ll explore how to safeguard your email infrastructure and prevent the kinds of cyberthreats that scammers and cybercriminals throw your way.
As this topic covers Part 6 of our guide, it’s also worth recapping on what we’ve explored so far, if you haven’t already:
Email security represents the next step in our guide, as another crucial aspect of robust modern business strategies. Here, we’ll cover their importance for modern businesses, and the threats posed by cyberattackers, before outlining four steps to secure your servers.
Why Focus on Email Servers?
Email servers form the backbone of your company’s communication network, managing all incoming and outgoing messages. Their security directly affects your organization’s trustworthiness and operational integrity. By properly configuring DNS records, you ensure secure and reliable email operations, much like installing a high-security lock on your mailbox. This approach prevents serious risks, such as email spoofing and corporate email compromise (BEC), where attackers could impersonate your domain and deceive recipients. By securing your email servers, you protect your communications and maintain trust.
Now that we’ve established the importance of securing your email servers, let’s explore the types of attacks scammers use to target them—and how you can defend against these threats.
Risks and Vulnerabilities of Email Servers
When brand fail to secure your email servers properly, cyberscammers exploit any weaknesses to launch their attacks. Typical threats include email spoofing attacks. In email spoofing attacks, cybercriminals impersonate your domain to send malicious emails. They trick recipients into believing the emails are legitimate, then manipulate their targets into revealing valuable details like logins, financial records, and personal information. By exploiting the trust between you and your contacts, attackers profit at their victims’ expense.
Corporate email compromise (BEC) poses another serious risk. Attackers craft fake emails that appear to come from within your organization, targeting employees and company partners. They trick their targets into transferring funds or sharing sensitive information, leading to financial losses and data breaches. BEC attacks exploit human trust and are often difficult to detect until it’s too late. Crucially, data breaches also lead to embarrassing press releases and fines and penalties from regulators.
Understanding these attacks is the first step in building strong defenses. Next, we’ll explore effective strategies for protecting your email servers from these threats.
Strategies for Protecting Your Email Servers
Here’s four foundational email server cybersecurity strategies straight from our CTO.
1. SPF (Sender Policy Framework): Defining your Authorized Mail Servers
SPF, or Sender Policy Framework, helps protect your domain from email spoofing by listing authorized mail servers in your DNS records. Think of SPF as a security guard at a gated community, only allowing residents (authorized servers) to send mail (emails) on behalf of your domain. This prevents imposters from sending fraudulent emails and enhances your email deliverability.
To set up SPF, first identify the mail servers authorized to send emails for your domain. Create an SPF record that specifies these servers and add it to your DNS zone file. Regularly update this record to reflect any changes in your mail infrastructure, ensuring continuous protection against unauthorized email sources.
2. DKIM (DomainKeys Identified Mail): Authenticating your Email Senders
DKIM, or DomainKeys Identified Mail, adds a crucial security layer by allowing recipients to verify that an email was sent from an authorized server and has not been altered. It works by generating a unique digital signature for each outgoing email and publishing the corresponding public key in your DNS records. This process helps recipients authenticate the email’s source, boosting trust and security.
Implementing DKIM involves generating a private key to sign your emails and a public key for your DNS records. Ensure that your email servers are configured to use this DKIM signature for outgoing messages. For businesses focused on stability and growth, expertise in managing these security measures is vital. Corporate Domain Management professionals provide essential support by enhancing domain security, allowing brands to maintain their priorities and achieve their goals. Their expertise ensures that your email security measures are robust and effective.
3. DMARC (Domain-based Message Authentication, Reporting & Conformance): Controlling your Email Delivery
DMARC, or Domain-based Message Authentication, Reporting, and Conformance, enhances email security by building on SPF and DKIM. Imagine DMARC as a well-trained security team at a VIP event. This team not only checks invitations (SPF and DKIM) but also decides how to handle guests who don’t have proper credentials, such as turning them away or alerting you to potential security issues.
To implement DMARC, create a DMARC record in your DNS zone and set policies for managing emails that fail authentication checks. This setup enables you to reject unauthorized emails and significantly reduces the risk of spoofing and phishing attacks. Proper DMARC configuration ensures robust protection for your email communications, keeping your digital environment secure.
4. NULL MX Record: Indicating Domains that Shouldn’t Receive Emails
For domains that don’t handle email, you can manage incoming mail effectively by setting up a NULL MX record. Think of a NULL MX record as posting a «No Mail Accepted» sign on your front door. It tells other mail servers that your domain doesn’t receive any emails. This action prevents unwanted email traffic and lowers the risk of spam targeting your domain.
An MX (Mail Exchange) record specifies which servers handle incoming emails for your domain. When you set an MX record, you designate servers to accept and process incoming emails. If your domain doesn’t handle email, use a NULL MX record with a value of “0” or “NULL” to inform other servers that no mail servers are available for your domain.
To implement a NULL MX record, add it to your DNS zone file for domains that don’t process email. Update your DNS settings to include a record that specifies “no mail servers” for your domain. By doing this, you block any incoming email traffic, keeping your domain free of unwanted spam and other email-related issues.
Conclusions: How Email Server Security Enhances Domain Protection
Securing your email servers with SPF, DKIM, DMARC, and NULL MX records proves essential for protecting your domain from email-based threats. These strategies ensure that your email communications stay secure, reliable, and trustworthy, safeguarding your organization against cyber threats. By implementing these measures, you enhance your email infrastructure security, improving your domain protection to protect your clients, your team, and your brand.
Thank you for following our series so far! In our final installment, we’ll cover the concept of risk prevention in domain cybersecurity. Tackling this topic through the lens proactive measures helps brands get a head start on scams and cyberattacks, as we’ll learn. Until then, stay tuned!
