Key Takeaways

• Email security policies help reduce phishing, spoofing, malware, business email compromise, account takeover, and accidental data exposure.
• Strong policies connect technical controls with human decision-making, especially around payments, attachments, links, sensitive data, and suspicious requests.
• Email authentication controls such as SPF, DKIM, and DMARC help protect domains from impersonation and spoofed messages.
• The best policies are specific enough to guide employees, IT, security, finance, legal, and compliance teams during real scenarios.
• Email security should connect to broader cybersecurity risk management, incident response, vendor risk, and compliance workflows.

Email remains one of the easiest ways for attackers to reach their victims. It sits at the center of normal business activity, which is exactly why attackers keep using it.

A good email security policy gives the organization a shared rulebook for how email should be protected. It explains which controls need to be in place, who owns them, how employees should handle suspicious messages, and what happens when something goes wrong.

That matters because email attacks are no longer limited to obvious spam or poorly written phishing messages. The FBI’s 2025 Internet Crime Report found that cyber-enabled crimes defrauded Americans of nearly $21 billion, with phishing and spoofing among the most frequently reported complaint types. The FBI also continues to describe business email compromise as one of the most financially damaging online crimes because it exploits the trust people place in normal business email.

The Attacks Email Security Policies Help Protect Against

Phishing Attacks That Try to Trick Employees

Phishing is usually the first attack people think of when they hear “email security.” That is fair. Phishing remains one of the most common ways attackers try to steal credentials, deliver malware, or convince someone to take an unsafe action.

Email security guidelines help by setting clear expectations for how employees should treat suspicious links, unexpected attachments, credential prompts, QR codes, and urgent requests. It should explain what employees should report, where to report it, and what they should avoid doing after they notice something suspicious.

The policy should also define the controls behind the scenes. That may include secure email gateways, link scanning, attachment sandboxing, anti-phishing training, warning banners for external emails, and phishing-resistant authentication for sensitive systems.

Business Email Compromise and Payment Fraud

Business email compromise, often called BEC, is different from basic phishing. It often uses a familiar name, a real business process, and a believable request. The message may ask for a wire transfer or a sensitive business document.

The FBI explains that BEC scams often appear to come from a known source, making a legitimate request. Email security use cases include fake vendor invoice changes, executive gift card requests, and fraudulent wire instructions. The FBI also notes that attackers may spoof accounts, send spearphishing messages, or use malware to access real email threads and time their requests more convincingly.

An email security policy helps protect against BEC by defining verification rules. For example, payment changes may require confirmation through a separate channel. Executive requests may require approval from a second person. Vendor banking changes may need to be verified using contact information already on file.

Email Spoofing and Domain Impersonation

Spoofing happens when attackers make a message look like it came from a trusted domain or person. Domain impersonation can be more subtle. The attacker may use a lookalike domain, a slight spelling change, or a display name that hides the real sender address.

An email security strategy should define how the organization protects its own domains and how it checks incoming messages. This usually includes SPF, DKIM, and DMARC.

SPF helps receiving servers check whether a sending server is authorized to send email for a domain. DKIM adds a digital signature that helps verify the message was not altered. DMARC builds on SPF and DKIM by telling receiving systems what to do when a message fails authentication.

CISA’s email security guidance and performance goals connect email authentication with reducing common email-based threats such as spoofing, phishing, and interception. CISA also recommends using controls such as SPF, DKIM, DMARC, and related email security settings across corporate email infrastructure.

Malware and Malicious Attachments

Email remains a common delivery method for malware. Attackers may send malicious attachments, links to infected files, fake document-sharing invitations, or compressed files that hide dangerous content.

An email security strategy helps by defining what file types are allowed, how attachments are scanned, which attachments should be blocked, and how users should handle unexpected files. The policy should also address cloud-based file sharing because many attacks no longer arrive as traditional attachments. A message may link to a fake Microsoft 365, Google Drive, Dropbox, or DocuSign page.

Microsoft’s 2025 Digital Defense Report highlights how financially motivated attacks continue to rely on cybercrime ecosystems, access brokers, infostealers, and credential theft. It also reported that 97% of identity attacks were password spray attacks, showing how email, identity, and credential protection now overlap heavily.

Credential Theft and Account Takeover

Account takeover attacks are designed to steal usernames, passwords, session tokens, or MFA prompts. Once attackers gain access to a real account mailbox, they can do far more damage. They can read old threads, create forwarding rules, impersonate the user, request payments, reset passwords, or send phishing emails from a trusted account.

This is where an email security policy should connect to an access control policy and broader IT security policies. The policy should address multi-factor authentication, password rules, mailbox access, forwarding restrictions, administrator privileges, suspicious login alerts, and offboarding.

Executive Impersonation and Internal Trust Abuse

Attackers often impersonate executives because authority creates pressure. A message from the CEO, CFO, legal counsel, or board member may cause employees to move quickly. That urgency is exactly what attackers use.

An email security policy should define special handling rules for executive requests. It should make clear that sensitive actions require verification, regardless of who appears to ask. This includes money movement, credential sharing, document release, payroll changes, legal approvals, and access changes.

The policy should also protect executives themselves. Executive mailboxes often need stronger monitoring, phishing-resistant MFA, delegated access rules, and tighter controls around forwarding and recovery options.

This is an email governance issue as much as a security issue. The organization should make it normal to verify sensitive requests. Verification should be treated as part of the business process, not as a sign of distrust.

What Email Security Policies Usually Include

A practical email security policy usually covers:

FAQs

What Is the Main Purpose of an Email Security Policy?

The main purpose is to define how the organization protects email systems, users, domains, and sensitive information. It should cover technical controls, user responsibilities, monitoring, reporting, and response steps.

Should an Email Security Policy Include DMARC?

Yes. DMARC should usually be included alongside SPF and DKIM. The policy should define who owns email authentication, how records are reviewed, and how the organization manages approved third-party senders.

How Does an Email Security Policy Help With BEC?

It creates verification rules for high-risk requests. This includes payment changes, wire transfers, executive requests, payroll updates, and vendor banking changes.

Who Should Own the Email Security Policy?

Security or IT usually owns the technical policy, but finance, legal, HR, compliance, and vendor management should contribute. Email attacks often target business processes, not only inboxes.

The post The Attacks Email Security Policies Help Protect Against appeared first on Centraleyes.

*** This is a Security Bloggers Network syndicated blog from Centraleyes authored by Rebecca Kappel. Read the original post at: https://www.centraleyes.com/the-attacks-email-security-policies-help-protect-against/