Sensitive data loss has long been an issue for organizations of all sizes. From phishing and ransomware to advanced threats, there is a long and growing list of ways that data can find itself outside your defenses. That said, it never really “finds itself” there. It ends up there accidentally or intentionally—and usually by employees. In fact, two-thirds of the CISOs that were surveyed for our 2024 State of the Phish report said their business experienced data loss due to an insider.
While there are many ways data loss happens, one common way is misdirected emails. These are messages that are accidentally sent to the wrong recipients. Unfortunately, these emails are difficult to stop with traditional tools because they aren’t flagged by standard rule-based data loss prevention (DLP) products. This leaves users responsible for ensuring that their emails are always sent to the intended recipients.
However, users often don’t even know that they’ve made a mistake. That’s why organizations need a better way to detect and prevent misdirected emails. Here, we’ll delve deeper into this issue and how to stop it.
What is a misdirected email?
A misdirected email happens when an email meant for one person is sent to someone else. Proofpoint research shows that 33% of users send an average of just under two misdirected emails each year. Here are some causes of misdelivered emails:
- Autocomplete errors. When typing a name or email address, email clients often suggest previously used contacts. In a rush, a user might choose the wrong recipient from the list.
- Simple mistakes. A slight misstep when typing an address, such as an extra letter or omitted part of a domain name, could result in a message going to the wrong recipient.
- Group emails. Sometimes, the confusion over recipient lists (especially in large organizations) leads to emails being sent to people outside an intended group.
The type of data exposed in these incidents can vary. Here are some examples:
- Intellectual property
- Financial documents
- Legal documents
- Engineering schematics and production data
- Customer lists and data
- Passwords
- Board meeting notes
- Personal identifiable information (PII)
- Personal health information (PHI)
Detecting and stopping misdirected emails
Rules-based email DLP is great at catching predefined known risks—rules can be written for those incidents. However, it can’t catch misdirected emails or email exfiltration of sensitive data to personal or unauthorized accounts. To prevent these data loss incidents, you need to take an adaptive, behavioral approach to email data security.
A behavior-based email DLP solution uses behavioral AI, machine learning (ML) and relationship graphing to learn from, adapt to, and predict human behavior. It detects potential data loss incidents even when the data isn’t well-defined. It continuously learns and evolves as user behavior evolves. This makes it the ideal approach for combating human-centric data loss.
Here’s why a behavior-based email DLP solution is so useful.
Validate recipients
A behavior-based email DLP solution can intelligently validate the recipient of an email before it is sent. By using ML to analyze normal email behaviors and patterns, the system can flag emails that are being sent to the wrong recipient. It doesn’t matter if it's an internal or external contact. This is especially helpful in preventing misaddressed emails.
Scan attachments
A behavior-based email DLP solution automatically scans email attachments. It ensures that they are the correct versions and that they don’t contain any sensitive data. It also uses relationship graphing to check that they are typically associated with the intended recipients. If attachments are missing, or being sent to a user not typically associated with it, the sender is notified before they hit “send.”
Analyze context
Contextual awareness means that the content and context of emails are analyzed for potential risks. For example, if an email contains sensitive financial or personal data, behavioral AI can assess whether it is appropriate to send that data to the recipient based on their context, such as their role within the organization.
Perform historical benchmarking
ML can analyze an organization’s historical email patterns, benchmark normal emails sending behaviors, and predict potential errors before they happen. This dynamic, proactive approach allows the system to suggest corrections in real time based on past behaviors and common mistakes,
Provide real-time alerts and coaching
A behavior-based email DLP solution provides real-time feedback to users. If an email appears to contain sensitive information or is being sent to the wrong or unauthorized recipient, the system will alert the sender immediately. This gives the sender a chance to correct the error before it’s too late. It also increases their email security awareness in the moment.
Conclusion
It’s an easy mistake to email the wrong person. But the consequences can be anything but trivial. However, when you have the right safeguards in place, you can effectively prevent such errors. AI-powered tools spot unusual email patterns and warn users, effectively enforcing security policies without impacting admin or security teams.
How Proofpoint can help
Proofpoint Adaptive Email DLP can help your business stop data loss by prompting users to correct the mistakes that lead to email misdelivery. Plus, it can automatically block attempts to send sensitive information to personal or unauthorized recipients.
Adaptive Email DLP integrates seamlessly into your existing workflows, preventing accidental or intentional data loss without disrupting the user experience. People write and send messages in the same way they always do. Meanwhile, the system operates in the background, intervening only when necessary. This means users only interact with the solution every few weeks rather than a few times a day. This significantly reduces the risk of warning fatigue, which can lead to a continued stream of data loss incidents.
Adoption is fast, too. There are no rules to implement and refine over time to balance security and user convenience—it is 100% automated. In most cases, Adaptive Email DLP is deployed in minutes, learns from historical messaging within hours, and is ready to protect your people and your data within days.
Real-world applications highlight its effectiveness. In one case, our solution prevented a merger and acquisition-related email from being sent to a journalist:
“We saw ROI in just one misdirected email prevented by Adaptive Email DLP.”
— General counsel, global law firm
Adaptive email DLP intervenes in the case of malicious insiders as well. Our solution helped a global financial institution spot and block attempts by a departing chief financial officer to send board meeting minutes and sensitive documents to a personal account.
“The platform is resonating—changing behavior and decreasing our level of risk.”
— CISO, global financial institution
Learn from our experts
Harness the power of behavioral AI to prevent accidental and intentional data loss over email. To find out more, visit our web page on Proofpoint Adaptive Email DLP. Or request a free data loss assessment to uncover hidden email exfiltration risks in your organization.
