How Email DLP Filters Work

Target

• Customers using Email DLP
  (For a list of features available for each contracted license, please refer to this page)

Contents

• This article explains how Email DLP Filter Settings work.

Notes

1. The content of this article is based on product specifications as of April 2025 and is subject to change without notice.
2. Please use the following article to confirm in advance that your environment meets the requirements for using Email DLP.
   HENNGE One System Requirements

Table of Contents

• Email DLP Overview
• Filter Settings Overview
• What Is an Address group?
• What Is a Rule Group?
• What Are Filters?

Email DLP Overview

Email DLP is a filtering service that integrates with Exchange Online and Gmail to help prevent misdirected emails sent externally.
In addition to features for preventing misdirected emails, such as suspending emails for a certain period or restricting the sending of emails that violate security policies, it also provides a feature for securely exchanging Attachments.

For Details, please refer to the following link.
Email DLP Overview

Filter Settings Overview

In Email DLP, filtering processes used to implement various measures for preventing misdirected emails are defined as Filter Settings.
As shown in the example below, Filter Settings are defined by selecting a priority, Sender, Recipients, Apply Predicate, and processing.

For emails sent externally from Microsoft 365 or Gmail, Email DLP verifies the Sender and Recipients, as well as whether the Apply Predicate for the processing is met, in order from the setting with the lowest priority value.
As a result, only the processing for the first setting in which the Sender, Recipients, and Apply Predicate all match is executed.

Each item must be defined as one of the Email DLP settings described below.

• Sender, Recipients: Address group
• Apply Predicate, processing: Rule Groups

What Is an Address group?

An Address group is a component of Filter Settings that defines the Sender and Recipients to which filtering processes are applied, by email address or Domain.
You can specify internal or external email addresses and Domains.

For instructions on setting up Address groups, please refer to the following article.
[Email DLP] Address Settings - Creating/Editing Address Groups

What Is a Rule Group?

A Rule Group is a component of Filter Settings that defines specific filtering processes and their Apply Predicates.
Rule Groups are defined using either a single Rule or a combination of multiple Rules with priority assigned.
Within each Rule, specific filtering processes and Apply Predicates are defined.

Example）If emails without Attachments are sent unmodified without any processing, while Attachments in emails with Attachments are converted to Secure Download, define the Rule Group as follows.

For instructions on setting up Rule Groups and Rules, please refer to the following articles.
[Email DLP] Filter Settings - Creating/Editing Rule Groups
[Email DLP] Filter Settings - Create/Edit Rules

What Are Filters?

Filters are settings that define the filtering processes to be executed in Email DLP.
Filtering processes are enabled in Email DLP only after Filter Settings have been configured.
Combine preconfigured Address groups and Rule Groups, assign priorities, and define the filtering processes to be used in actual operations.

For instructions on setting up Filters, please refer to the following article.
[Email DLP] Filter Settings - Creating/Editing a Filter

Related Articles

・[Email DLP] User Guide

Translation Disclaimer

This article has been automatically translated from the original Japanese version for your convenience.
While we strive to ensure accuracy, we cannot guarantee its reliability or completeness.

In the event of any discrepancies or questions regarding the content, the official Japanese version shall prevail.