Policies - Data Leak Prevention

This article contains information on Mimecast's Data Leak Prevention (DLP) features, including policies, secure messaging, and large file send, to protect sensitive data, prevent leaks, and ensure compliance while maintaining productivity.

Your organization's value and competitive advantage are inextricably linked to the knowledge you hold. Information such as new product ideas, future business plans, and customer data represents an invaluable business asset. It can be shared easily with colleagues and third parties via email when stored digitally. While this flexibility brings great benefits, it also increases the risk of data leakage. The repercussions on your organization of a data leak can be severe, including:

• • • Fines.
    • Loss of reputation.
    • Legal action.

Mimecast's DLP Benefits

Mimecast protects against an organization-wide data leak through seamless integration with Microsoft Exchange. Using our cloud-based service, it:

• • • Protects against honest mistakes and malicious intent.
    • Ensure controls are put in place that do not stifle productivity.
    • Provides flexibility to allow your IT department to implement an email security policy that stipulates what:
      • Content can be emailed between a sender and a recipient.
      • Email data can be stored.
    • Ensures evidence is safeguarded that establishes who was involved in a data leak and the context in which it occurred.
    • Educates users on policy and best practices.

Policies

Mimecast uses a series of policies defined by your administrator using Mimecast's Administration Console, with any changes applied in real time. It doesn't matter how many sites or email servers you have; your email security policies are applied consistently to all email traffic. You can:

• • • Apply controls to specific users and groups.
    • Ensures email signatures and legal notices are applied through integration with your directory.
    • Examine a message's body text, HTML, headers, subject lines, and attachments to look for:
      • Defined words.
      • Text patterns.
      • Inappropriate images.

The following policies can be used for data leak prevention:

Policy	Description
Content Examination	Provides a comprehensive DLP system that secures information entering and leaving your organization. Content Examination policies use a Content Examination Definition to specify the content to look for and what action should be taken if a match is found. You can use various techniques to catch undesirable content, including Managed Reference Dictionaries, Healthcare Dictionaries/Entities, Regular Expressions, and Fuzzy Hashing. The policy applies the definition to either inbound or outbound email scanning. In addition, message delivery can be prevented using the hold queue, and notifications can be enabled for specific senders, recipients, or groups of users. You can configure a Content Examination policy to duplicate the actions of all the other policies listed. This prevents having to set up other policies to meet your DLP requirements. See the Match Examples page for tips on using this policy. You can use fuzzy hashing in a Content Examination definition to compare two distinctly different items and determine a level of similarity expressed as a percentage between the two. This can limit the flow of sensitive information from leaving your organization by matching content similarities between a control document and email attachments passing through your Mimecast service. See the Fuzzy Hashes page for full details.
Configuring Attachment Management	Restricts what attachments are allowed in and out of your organization by enabling administrators to apply granular attachment handling for individual attachment types within inbound or outbound messages.
Group Carbon Copy	Allows individuals or groups to be blindly copied on messages based on the email flow. The sender and recipient of the message are unaware that this action occurs.
Metadata Preservation (Minutes)	Allows you to limit the life of message metadata to a value less than your organization's maximum Account Retention. Email metadata (including the email header) is the associated information present in an email message.
Metadata Preservation (Days)
Configuring Document Services Definitions and Policies	Control attachments sent or received from your organization. This policy can remove confidential metadata from documents or convert documents to PDF/ODF before being delivered to the recipient.
Secure Delivery	These use Transport Layer Security (TLS) technology, which protects confidentiality and data integrity by encrypting connections between servers, ensuring emails are transmitted through an SSL-encrypted tunnel. This reduces the risk of eavesdropping, interception, and alteration of emails as they are sent across the internet.

Other Considerations

Mimecast can provide additional add-on products that can help with your DLP strategy. These include:

• • • Secure Messaging.
    • Large File Send.

Secure Messaging

Secure Messaging lets you share sensitive information with people outside your organization without the message leaving our secure network. For example, you can create a message inside your email client but select to send it securely. Additionally, a policy can be configured by your administrator to be applied automatically at the gateway.

Secure Messaging provides:

• • • A secure, private, cloud-based service enables the sharing of sensitive information directly from your email client.
    • Straightforward message and file access via a secure web portal give recipients a consistent experience from any device.
    • Fully customize the branding of the secure web portal to ensure brand recognition and enhance recipient confidence.
    • Configurable expiration dates, read receipt, no print, reply, forward restriction, and revoking access. This can be applied by the sender or set using policies.
    • Tighter protection than just the server-to-server encryption by removing an administrator's ability to view in-transit messages.

See the Secure Messaging page for full details.

Large File Send

Large File Send allows end users to send large files that bypass your Exchange to an internal or external user. This can be achieved manually via the Mimecast for Outlook ribbon inside Microsoft Outlook or the Mimecast for Mac application. Alternatively, your administrator can create a policy to automatically send a message via Large File Send when certain attachment conditions are met. For example, senders can choose how long the attachment is available to download, and all existing DLP policies can be applied as the messages pass through Mimecast.

Large File Send allows:

• • • Users to send and receive files up to 2 GB in size.
    • Users create a message in their email client, just like small files.
    • Administrators to set policies for attachment size. The Mimecast cloud does the rest.
    • Seamless integration into Outlook for Windows, Outlook for Mac, or delivered via a Mimecast mobile application.
    • Support audit, e-discovery, and compliance requirements by archiving files and notification policies.

See the Large File Send - Overview page for full details.

See Also...

• • • Message Center - Monitoring Held Messages
    • Monitoring Data Leak Prevention
    • Content Examination - Getting Started