Mail Security is a class of solutions that filters inbound and outbound corporate email to block phishing, malicious attachments and links, spam, and business email compromise (BEC) attacks. Email remains the primary entry point into corporate infrastructure, so protecting it is a foundational element of corporate security.
What threats Mail Security protects against
Mail Security covers nearly the full spectrum of email threats — from mass spam to targeted attacks on specific employees. The main categories are:
- Phishing — emails designed to steal credentials and payment details.
- Malicious attachments and links — documents and archives carrying payloads, links to fake websites.
- BEC (Business Email Compromise) — sender spoofing and compromise of business correspondence, usually without attachments.
- Spam and unwanted mailings, which create noise and risk.
How email protection works
Email protection works in layers: a message passes through several checks before it reaches the user's inbox. Typical mechanisms include:
- Reputation checks on the sender and the sending infrastructure.
- Sender authentication via SPF, DKIM, and DMARC to combat address spoofing.
- Attachment analysis, including in an isolated environment (sandbox).
- Link inspection, including at the moment the user clicks.
- Content and behavioral analysis to detect signs of phishing and BEC.
The exact set of engines and technologies in a given product should be verified against current documentation.
How Mail Security differs from a mail server's built-in protection
In short: a mail server's built-in filters catch basic spam, but they're usually not enough against targeted attacks. A dedicated Mail Security solution provides deeper analysis of attachments and links, defenses against BEC and sender spoofing, flexible policies, and transparent reporting for the security team. For distributed organizations, scalability and centralized management also matter.
How to choose an email protection solution
When choosing Mail Security, focus on the completeness of protection, ease of operation, and fit with your infrastructure. Useful criteria:
- Threat coverage: phishing, BEC, malicious attachments and links.
- Quality of attachment and link analysis, and availability of sandboxing.
- Support for SPF, DKIM, DMARC and handling of sender spoofing.
- Policy flexibility and ease of incident triage.
- Compatibility with your existing mail infrastructure and deployment model (on-premises or cloud).
For companies operating in Russia, additional factors include listing in the domestic software registry and regulatory requirements — check the product documentation for specifics.
Why SPF, DKIM, and DMARC matter
SPF, DKIM, and DMARC are three DNS records that together verify sender authenticity and make address spoofing much harder. They work as a set:
- SPF specifies which servers are authorized to send mail on behalf of a domain.
- DKIM adds a cryptographic signature to a message, confirming it hasn't been tampered with.
- DMARC sets the policy: what to do with messages that fail SPF and DKIM checks, and where to send reports.
Without these records, it's easier for an attacker to impersonate your domain — so configuring them is the foundation of email protection that the rest of Mail Security's mechanisms build on.
On-premises or cloud
Mail Security can be deployed either on-premises or in the cloud — the choice depends on data control requirements and organization scale. On-premises deployment offers maximum control and is often required by regulators, while cloud deployment launches faster and scales more easily. Check the product documentation for the specific supported scenarios.
Why training specialists matters
Even a strong solution requires properly configured policies and skilled incident triage. Configuration mistakes either let attacks through or block legitimate mail — which can hurt business processes just as much as the attack itself. That's why training engineers and email security specialists directly affects outcomes. A practical checklist for phishing and BEC protection is covered in a separate article, "Protection Against Phishing and BEC".
Hands-on practice on BI.ZONE Cybersecurity Labs
Email protection is best learned on real infrastructure. In the BI.ZONE Mail Security course, you configure filtering policies, analyze detections, and practice defense scenarios against common attacks on isolated lab environments. Product capabilities are described on the BI.ZONE Mail Security page, and you can start training on the course page.