An Introduction to Amazon WorkMail Audit Logging

Important Update (10/31/2024) - Amazon WorkMail now supports multi-factor authentication (MFA) through integration with AWS IAM Identity Center! Please see the What's New announcement and the Amazon WorkMail documentation for more information.

Amazon WorkMail’s new audit logging capability equips email system administrators with powerful visibility into mailbox activities and system events across their organization. As announced in our recent “What’s New” post, this feature enables the comprehensive capture and delivery of critical email data, empowering administrators to monitor, analyze, and maintain compliance.

With audit logging, WorkMail records a wide range of events, including metadata about messages sent, received, and failed login attempts, and configuration changes. Administrators have the option to deliver these audit logs to their preferred AWS services, such as Amazon Simple Storage System (S3) for long-term storage, Amazon Data Firehose for real-time data streaming, or Amazon CloudWatch Logs for centralized log management. Additionally, standard CloudWatch metrics on audit logs provide deep insights into the usage and health of WorkMail mailboxes within the organization.

By leveraging Amazon WorkMail’s audit logging capabilities, enterprises have the ability to strengthen their security posture, fulfill regulatory requirements, and gain critical visibility into the email activities that underpin their daily operations. This post will explore the technical details and practical use cases of this powerful new feature.

In this blog, you will learn how to configure your WorkMail organization to send email audit logs to Amazon CloudWatch Logs, Amazon S3, and Amazon Data Firehose . We’ll also provide examples that show how to monitor access to your Amazon WorkMail Organization’s mailboxes by querying the logs via CloudWatch Log Insights.

Email security

Imagine you are the email administrator for a biotech company, and you’ve received a report about spam complaints coming from your company’s email system. When you investigate, you learn these complaints point to unauthorized emails originating from several of your company’s mailboxes. One or more of your company’s email accounts may have been compromised by a hacker. You’ll need to determine the specific mailboxes involved, understand who has access to those mailboxes, and how the mailboxes have been accessed. This will be useful in identifying mailboxes with multiple failed logins or unfamiliar IP access, which can indicate unauthorized attempts or hacking. To identify the cause of the security breach, you require access to detailed audit logs and familiar tools to analyze extensive log data and locate the root of your issues.

Amazon WorkMail Audit Logging

Amazon WorkMail is a secure, managed business email service that hosts millions of mailboxes globally. WorkMail features robust audit logging capabilities, equipping IT administrators and security experts with in-depth analysis of mailbox usage patterns. Audit logging provides detailed insights into user activities within WorkMail. Organizations can detect potential security vulnerabilities by utilizing audit logs. These logs document user logins, access permissions, and other critical activities. WorkMail audit logging facilitates compliance with various regulatory requirements, providing a clear audit trail of data privacy and security. WorkMail’s audit logs are crucial for maintaining the integrity, confidentiality, and reliability of your organization’s email system.

Understanding WorkMail Audit Logging

Amazon WorkMail’s audit logging feature provides you with the data you need to have a thorough understanding of your email mailbox activities. By sending detailed logs to Amazon CloudWatch Logs, Amazon S3, and Amazon Data Firehose, administrators can identify mailbox access issues, track access by IP addresses, and review mailbox data movements or deletions using familiar tools. It is also possible to configure multiple destinations for each log to meet the needs of a variety of use cases, including compliance archiving.

WorkMail offers four audit logs:

• ACCESS CONTROL LOGS – These logs record evaluations of access control rules, noting whether access to the endpoint was granted or denied in accordance with the configured rules;
• AUTHENTICATION LOGS – These logs capture details of login activities, chronicling both successful and failed authentication attempts;
• AVAILABILITY PROVIDER LOGS – These logs document the use of the Availability Providers feature, tracking its operational status and interactions feature;
• MAILBOX ACCESS LOGS – Logs in this category record each attempt to access mailboxes within the WorkMail Organization, providing a detailed account of credential and protocol access patterns.

Once audit logging is enabled, alerts can be configured to warn of authentication or access anomalies that surpass predetermined thresholds. JSON formatting allows for advanced processing and analysis of audit logs by third party tools. Audit logging stores all interactions with the exception of web mail client authentication metrics.

WorkMail audit logging in action

Below are two examples that show how WorkMail’s audit logging can be used to investigate unauthorized login attempts, and diagnose a misconfigured email client. In both examples, we’ll use WorkMail’s Mailbox Access Control Logs and query the mailbox access control logs in CloudWatch Log Insights.

In our first example, we’re looking for unsuccessful login attempts in a target timeframe. In CloudWatch Log Insights we run this query:

fields user, source_ip, protocol, auth_successful, auth_failed_reason | filter auth_successful = 0

CloudWatch Log Insights returns all records in the timeframe, providing auth_succesful = 0 (false) and auth_failed_reason = Invalid username or password. We also see the source_ip, which we may decide to block in a WorkMail access control rule, or any other network security system.

Mailbox Access Control Log – an unsuccessful login attempt

In this next example, consider a WorkMail organization that has elected to block the IMAP protocol using a WorkMail access control rule (below):

WorkMail Access Control Rule – block IMAP protocol

Because some email clients use IMAP by default, occasionally new users in this example organization are denied access to email due to an incorrectly configured email client. Using WorkMail’s mailbox access control logs in CloudWatch Log Insights we run this query:

fields user_id, source_ip, protocol, rule_id, access_granted | filter access_granted = 0

And we see the user’s attempt to access their email inbox via IMAP has been denied by the access control rule_id (below):

WorkMail Access Control logs – IMAP blocked by access rule

Conclusion

Amazon WorkMail’s audit logging feature offers comprehensive view of your organization’s email activities. Four different logs provide visibility into access controls, authentication attempts, interactions with external systems, and mailbox activities. It provides flexible log delivery through native integration with AWS services and tools. Enabling WorkMail’s audit logging capabilities helps administrators meet compliance requirements and enhances the overall security and reliability of their email system.

To learn more about audit logging on Amazon WorkMail, you may comment on this post (below), view the WorkMail documentation, or reach out to your AWS account team.

To learn more about Amazon WorkMail, or to create a no-cost 30-day test organization, see Amazon WorkMail.

About the Authors

Luis Miguel Flores dos Santos

Miguel is a Solutions Architect at AWS, boasting over a decade of expertise in solution architecture, encompassing both on-premises and cloud solutions. His focus lies on resilience, performance, and automation. Currently, he is delving into serverless computing. In his leisure time, he enjoys reading, riding motorcycles, and spending quality time with family and friends.

Andy Wong

Andy Wong is a Sr. Product Manager with the Amazon WorkMail team. He has 10 years of diverse experience in supporting enterprise customers and scaling start-up companies across different industries. Andy’s favorite activities outside of technology are soccer, tennis and free-diving.

Zip

Zip is a Sr. Specialist Solutions Architect at AWS, working with Amazon Pinpoint and Simple Email Service and WorkMail. Outside of work he enjoys time with his family, cooking, mountain biking, boating, learning and beach plogging.