The Importance of Email DLP for Remote Organizations

Updated Jan. 1, 2024

Email is a popular channel for hackers: phishing attacks and malware usually originate from email. A staggering 94% of organizations experienced an email phishing attack last year according to the Egress Email Security Risk Report 2024. Even more striking is the percentage of employees who are punished, ostracized, or even fired for succumbing to these surgically precise attacks. Studies show that 51% of people who fall for phishing attacks are disciplined, and 39% are fired.

Does it really need to be this way? Email is an integral part of working remotely, increasing the likelihood that your organization is frequently the target of email-based attacks. Security teams are aware of this channel and its risks as a threat vector for unauthorized access and data exfiltration.

Email data loss prevention tools monitor a company’s email communications to determine whether data is at risk of loss or theft. With the email security market valued at $9.22 Billion last year, it's not like companies aren't trying to protect themselves. Let's explore ways people are solving for email DLP and why or why not those solutions don't seem to be working.

What is email DLP?

Email DLP is often considered a subset of network DLP — and many network DLP platforms monitor email for inappropriate use of data. However, organizations that take an integrated data loss prevention (IDLP) approach and use discrete, decentralized tools, may need to implement a separate email DLP solution capable of more accurate data detection and automated enforcement of security policies at the user level.

Traditional email DLP tools prevent sensitive information from being sent or shared outside the organization. Some tools also include features to defend against inbound threats, such as spear phishing, business email compromise, or CEO fraud.

Why is email DLP so important for remote and hybrid workplaces?

Remote employees typically use personal devices, are not tied into corporate networks, and utilize their own private internet connections. This tech setup typically also means less (or no) visibility into ingress and egress web traffic, users' data handling activities, and reduced effectiveness for data loss prevention solutions.

Remote work is a major bonus for many desirable employees in 2025, however, and is often necessary to not only maintain the best talent, but minimize overhead for expensive office spaces.

Secure Email Gateways Aren't Working

Many organizations use email gateway solutions with embedded DLP features in an effort to solve for potential data loss. While these solutions can reduce the risk of ransomware attacks from coming in as piggybacked traffic, they're not always the best choice for data loss prevention. Functionally, their goal is to look for suspicious activity at both ingress and egress using a list of potential red flags as criteria.

What Your Gateway Should Be Doing

Spam and graymail filtering: This is a key functionality of email gateways, helping them to act as your email's bouncer. Filtering helps spot spam and marketing emails to reduce clutter and the potential of accidentally clicking on adware or click bait.

Malicious content protection: Malicious filtering identifies suspicious links, sketchy attachments, and the presence of other potential red flags. Very well written social engineering attacks can still escape detection, so it's still important to train employees on prevention and risk avoidance techniques.

Data loss prevention: This is where most email solutions break down. Email DLP should be watching your outgoing emails like a hawk, ensuring employees don't accidentally (or intentionally) send sensitive company information to unauthorized recipients. This only works, however, if the tool has the most powerful detectors to identify tricky sensitive data types. Otherwise, it's likely to result in a lot of false positives or miss security incidents altogether.

Email encryption: Encryption scrambles messages and attachments so only people with the decryption key can read it. This is essential for compliance with regulations designed to protect sensitive data during necessary file transfers. It can also help prevent leakage of other valuable assets like PII, intellectual property, and other data that may be in the body of an email.

Due to ineffectiveness of these tools, 91% of people using a secure email gateway (SEG) expressed frustration with its inaccuracy and inadequacy during a recent survey, and 87% are seeking to replace their SEGs.

If you're currently not satisfied that your teams are using best security practices and SEG isn't helping curb the risk, we highly suggest adding a powerful email DLP tool to your email security stack.

How does email DLP work?

Especially for remote organizations, email is the most common way for teams to communicate longer messages to one another, as well as collaborate with external vendors and third-party contractors. This also means it’s the most likely way that an employee could expose sensitive data, intentionally or not. Many email DLP tools work to eliminate insider threat: any action that compromises the security of an organization’s data.

Insider threats are risks that happen by accident, neglect, or malicious intent. Email DLP can be used to anticipate and reduce the threat of human error (or malicious intent) by enforcing a set of email flow rules.

Flow rules are set by the administrator to scan and filter email message content and attachments, looking for keywords, dictionary matches, and text patterns. Legacy email DLP rules tend to be somewhat static, based on criteria such as data sensitivity that are applied in a one-size-fits-all approach. Next-gen solutions will automatically detect sensitive data using advanced AI and ML models.

What does this look like in practice? Imagine a CPA preparing a tax return for a client. The CPA attaches the return in a PDF, adds the client's email address in the “to” field, and CCs their assistant for billing purposes. When the CPA hits send, the email DLP tool is triggered.

The tool would scan the PDF, the email body, and the user permissions of the assistant, CPA, and client. It would compare the content to a set of pre-set rules to see if the email contains sensitive information.

If the email DLP scan finds sensitive information, it may:

Ask the sender to modify the email before sending it by removing sensitive information that can’t be sent to external domains or applying encryption.
Ask the sender to verify recipients and attachments.
Reject or quarantine the email.
Give the user the ability to turn on encryption for the email.
Automatically modify the message through pre-built rules within the DLP software (i.e., applying email encryption).

The CPA would have to modify or encrypt the email if the tool finds sensitive information that shouldn’t be sent in plain text through this channel.

Best practices

Remote organizations need to be able to communicate seamlessly in today's global business landscape. It can be frustrating when an email DLP tool quarantines an email or prevents an employee from sending information. It’s important to set up your email DLP tool in such a way that enables employees to do their work without interruption — but still keeps your data secure.

Inventory your company’s sensitive data.

Start by defining what sensitive information your remote organization will need to protect. This can include PHI and PII such as:

Account numbers
Intellectual property, including code
Trade secrets
Social Security numbers
Health records
Credit card numbers
Salaries
Files containing login IDs and user passwords
Secrets like tokens or API keys

There may be compliance regulations that complement your understanding of the PII, PHI, and other valuable information you need to protect, like the GDPR or other regional laws. Remote work environments and global businesses often need to consider not just the regions of their business headquarters, but also the locations of employees and customers.

Use email encryption.

Email encryption is an authentication process that prevents messages from being read by an unauthorized individual. Encryption tools scramble the original message content, converting the text into an unreadable format. The recipient will have the private key to decode the email.

Many email DLP programs will have encryption software built in. Most encryption services rely on gateway software that enables the enforcement of policy-based encryption. You can also install encryption software on your employees’ devices. Email encryption is a must-have for every remote organization, as unauthorized users cannot view encrypted content even if they access the device, avoiding a potentially catastrophic data breach.

Antivirus Software

Using endpoint malware prevention like SentinelOne that leverages heuristics, powerful ransomware detection, and a host of automated remediation capabilities may be a better choice than an email gateway for the same purpose. This can ensure teams have backup protection in case they become more vulnerable to phishing or other email social engineering attacks in remote work scenarios.

Look for dynamic email DLP.

In the example above, we described a rules-based, traditional email DLP tool. Dynamic email DLP tools are able to evaluate the context, as well as the keyword. Through machine learning, these tools can understand when a message is anomalous or suspicious. Algorithms are constantly reclassifying data and learning about communication norms between a business and customers, suppliers, and other third parties. Look for an email DLP tool, like the one that Virtru built on top of Nightfall's Developer Platform. Solutions like this are able to set static rules in tandem with intelligent scanning to achieve the right balance of security and usefulness.

Email vs. cloud DLP: what’s the difference?

While email remains the core communication channel for professionals, more and more remote organizations are using cloud-based programs like Slack to share information. Email DLP software doesn’t protect information shared in these cloud channels. It can be cumbersome to maintain too many solutions and providers, so may want to find a comprehensive cloud - SaaS - email DLP solution with a powerful detection engine.

Cloud DLP tools like Nightfall AI help organizations discover, classify, and protect their most sensitive data in SaaS, PaaS, and IaaS platforms. Similar to email DLP, the best cloud DLP tools use machine learning to assess the context when data is shared. For instance, Nightfall uses AI to efficiently discover, classify, and protect data in the cloud by integrating directly with popular platforms – like Slack, Jira, and Google Drive at the API level.

Nightfall AI Cloud DLP with Email DLP and Encryption

Collaborative Approach to Insider Risk Management

Nightfall provides a collaborative platform that not only automatically prevents data exposure in unsanctioned cloud locations–including email– but also uses predefined policies to identify human mistakes with sensitive data and automate security workflows. Among those workflows is one we call the "human firewall", which essentially makes your employees an additional layer of security by inviting them to self-remediate errors. In turn, this reduces potential risks of unauthorized disclosure by improving data hygiene habits over time–a measure which has been shown to improve your organization's exposure drastically over time.

Cloud DLP for All Your Sensitive Data Types

Nightfall scans both structured and unstructured data, with the capability to parse text from 100+ file types, including customer chat logs, JSON objects, application logs, spreadsheets, PDFs, images, screenshots, and more. Incorporating accurate, automated DLP for email helps ensure your organization won't fall prey to a security breach via email, using human layer security.

Malicious Insider Risk Mitigation

Nightfall stops malicious insiders by giving you real-time visibility into user data handling activities and automating remediation in the event users don't complete self-remediation within the period of time you specify. When you investigate these events, you'll have all the context you need to understand the user's suspicious behavior and stop bad actors.

Why We Did It This Way

This dual approach addresses security challenges that can be difficult to solve for with other solution types. For example, user activity monitoring solutions tend to be punitive and surveillance-related, preventing them from constructive use in employee education and overall insider risk mitigation surrounding mistaken violation of security measures. You need the majority of your workforce–well meaning employees–to partner with you, not feel surveilled and untrusted by their security team. By improving your internal security user experience, you can work together with your teams to protect attack surfaces like email, meet compliance requirements, and improve your overall security strategy.

Nightfall's Endpoint Solution

In addition to comprehensive cloud DLP across cloud workspaces, SaaS, and email through tight integrations with mission-critical software, Nightfall also offers a browser-based solution for the endpoint. Our endpoint agent is a fantastic way to address insider risk as an extremely light solution that's fast, works in real-time, extends protection against unauthorized transmission to any cloud location, including unsanctioned cloud repositories. The Nightfall agent has all the same great features you're used to from Nightfall, so you can know your organization is protected against unauthorized sharing or other data handling mistakes as part of users' endpoint activity.

In Conclusion

Remote work requires email and cloud programs: companies simply can’t function without easy file sharing, streamlined communication, and shared collaboration tools. Layering email, email encryption, and cloud DLP makes it possible to reduce the risk of insider threats to business-critical data and still keep communication flowing smoothly.

Learn more about Nightfall by scheduling a demo today.

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The Importance of Email DLP for Remote Organizations