Armorblox is now part of Cisco

Articles & Thought Leadership | 9 min read

Email DLP Best Practices to Protect Your Data


Lauryn Cash
Lauryn Cash

Does worrying about business data loss keep you up at night? Learn about email DLP best practices that keep your data safe from internal and external threats.

Learn about six email DLP best practices to keep your data safe from internal and external threats.

Does the thought of email business data loss keep you up at night? The sheer volume of sensitive data that one can transmit via email is staggering. Therefore, preventing data loss through email DLP best practices is vital to maintaining your long-term data security.

Data loss prevention, or DLP, is an umbrella term that covers the strategies and techniques that businesses use to protect sensitive data. Email data loss prevention endeavors to stop data loss via email transmission.

In addition to threats posed by malicious attachments and malware coming from outside sources, employees can blast sensitive data to external sources — whether intentionally or by accident — by simply clicking “send.”

Adding DLP best practices to your IT strategy is an excellent place to start if you're serious about email security. Today we’ll review six email DLP best practices that keep your data safe from internal and external threats:

  1. Identify and control sensitive data
  2. Use data encryption
  3. Use email DLP software
  4. Enforce security policies and procedures
  5. Use multi-factor authentication
  6. Train employees on security protocols

1. Identify and Control Sensitive Data

How can you protect what you haven’t identified? Conducting an inventory of your company’s sensitive data is the first step in setting a DLP plan into motion. While critical data varies from business to business, common types of data that you should inventory include:

  • Account numbers
  • Intellectual property and trade secrets
  • Social Security numbers and other Personally Identifiable Information (PII)
  • Health records and other Protected Health Information (PHI)
  • Credit card numbers (subject to PCI DSS standards)
  • Salaries
  • IP addresses
  • Files containing login IDs and user passwords
  • Press releases in draft mode
  • Source codes

Keeping sensitive information out of the wrong hands is a priority, as it also avoids potential financial and legal penalties.

Once you’ve identified the information you’re protecting, it’s vital to answer the following questions to keep it safe:

  • Where is sensitive data stored?
  • What rules are in place for accessing sensitive data?
  • When is sensitive data archived, and for how long?

Where Is Sensitive Data Stored?

Is critical data siloed behind secure gateways, or is it stored haphazardly in network drives that anyone can get into? Knowing where your data resides is the first step in protecting it.

What Rules Are in Place For Accessing Sensitive Data?

Even if information is secured, can it be accessed at any time or for any reason? Creating controls around data keeps it safe and helps identify those who can exfiltrate it. For example, access control lists, or ACLs, keep tabs on who can access resources and how often.

When Is Sensitive Data Archived, And For How Long?

Depending on your industry or compliance issues, data is often subject to required storage time limits. The longer critical information is exposed, the more likely it is to be corrupted or stolen. Putting archiving protocols in place keeps data safe.

2. Use Data Encryption

Encrypting data on computers and laptops helps mitigate loss if devices are stolen or damaged. When a user opens an encrypted file, decryption software decrypts the file and enables the user to view or modify the unencrypted copy.

The copy is then saved and securely re-encrypted. However, unauthorized users cannot view encrypted content even if they can access the device, preventing data breaches.

3. Use DLP Software

There’s no use beating around the bush: Having a DLP program isn’t complete without using DLP software.  Email DLP software is a must in the war against business data loss.

An email DLP system typically monitors your corporate network’s entry and exit points (like user devices, servers, gateways, and email clients). In addition, sophisticated DLP tools use Natural Language Understanding (NLU), Natural Language Processing (NLP), and Machine Learning to provide visibility into sensitive data at rest or in transit within and outside your organization.

DLP software monitors, detects, and flags suspicious email activity to prevent sharing of sensitive data with unauthorized recipients over email.

4. Enforce Security Policies and Procedures

While DLP software is a highly effective tool, it cannot exist in a vacuum. Therefore, creating security policies and procedures for handling DLP scenarios is critical for getting your team on board and keeping incidents at bay.

At a minimum, your IT security policies should include the following.

Password Security Policies

Secure password policies encompass password length and complexity guidelines, along with time-based, forced password change requirements.


BYOD (Bring Your Own Device) and MDM (Mobile Device Management) policies have increased exponentially in the work-from-home era, as 59% of organizations are predicted to adopt BYOD in 2022.

However, you leave your company and employees exposed to cybersecurity threats that can rapidly infiltrate your network without strict guidelines governing mobile devices.

Patch Management Policies

Patch management policies contain requirements and guidelines covering the deployment, testing, and documentation of security patches to computer networks and software.

Unfortunately, you expose your system to zero-day cyberthreats and other security vulnerabilities without regular patch management.

Security Access Limitation Policies

The “principle of least privilege” describes the practice of offering users only the privileges necessary to complete their work. If you create an environment of “superusers” who can access your entire network unabated, you put your company at risk of having malware attacks spread quickly throughout your organization.

5. Use Multi-Factor Authentication

Multi-factor authentication, or MFA, has become a fairly standard security practice. While having an official MFA protocol is preferable, you can also replicate two-factor authentication (2FA) or MFA for any email that makes unusual requests.

How do you “replicate” MFA without specific tools? Go with your gut. If an email request looks suspicious, contact the sender directly before taking action on a particular request. It’s better to be safe than accidentally sending a list of Social Security numbers to the wrong person.

6. Train Employees

When it comes to cybersecurity, the human layer is the most vulnerable to making errors in judgment. Therefore, training employees on security protocols is never a “one and done” proposition. With cyberattacks and the likelihood of mistakes increasing, it’s vital to stay current with evolving threats and best practices and pass that information to your employees.

While identifying sensitive data, using data encryption and DLP software, enforcing security policies and procedures, and using MFA can help protect you from cyberthreats, they aren’t always enough. Because the human layer often falls victim to social engineering attacks, leaving people as the last line of defense is a recipe for disaster.

Supplement Your Data Loss Prevention Best Practices With Armorblox

As long as humans use technology, we will face security issues. However, you can lessen the impact of data breaches by implementing a data loss prevention strategy that includes email DLP software.

Armorblox leverages sophisticated language models to detect PII, PCI, and unencrypted passwords shared with unauthorized recipients, giving you an accurate snapshot of your organization’s data exposure risk.

In addition, Armorblox protects against inbound security threats (like spear phishing, Business Email Compromise (BEC), vishing), outbound threats (like data exfiltration and misdirected emails), and other advanced attacks that get past traditional security layers.

Modern email security goes beyond simple manual policies and blocklists to protect your human layer from compromise. Instead, Armorblox analyzes thousands of signals, learns from every organization and user, and automatically remediates threats before they cause harm.

To learn more about Armorblox, take a quick product tour below.

Take DLP Product Tour

Experience the Armorblox Difference

Get a Demo