Email Security/Exchange Online - Ensure Exchange Online Spam Policies are Set to Notify Administrators

By Ashwin Venugopal -

 








Summary

The organizations having Microsoft 365 with mailboxes in Exchange Online or standalone Exchange Online protection (EOP) organizations without the Exchange Online mailboxes, email messages are automatically protected against spam (junk email) by EOP.

Exchange Online Spam Policies can be configured to copy emails and notify someone when a sender in your tenant has been blocked for sending spam emails. 

Reason

If an account is blocked, that means, it has been breached and an attacker has been using it to send spam emails to other people.

Note- Audit and Remediation guidance may focus on the Default policy, but, if a Custom Policy exists in the organization's tenant then, it should be ensured that the setting is set as outlined in the highest priority policy listed.

What If?

The blocked notifications does not affect the users. 

How to?

To set the Exchange Online Spam Policies correctly, use the Microsoft 365 Admin Center:
  1. Go to the Microsoft Admin Center and click Security.
  2. Under Email & collaboration > Policies & rules > Threat policies > Anti-spam policies
  3. Now, select Anti-spam Outbound policy (default).
  4. Select Edit protection settings then under Notifications
  5. Check Send a copy of outbound messages that exceeds these limits to these users and groups then enter the desired email addresses.
  6. Check Notify these users and groups if a sender is blocked  due to sending outbound spam then enter the desired email addresses.
  7. Click Save.

To set the Exchange Online Spam Policies correctly, use the Exchange Online PowerShell Module:
  1. Connect to Exchange Online using Connect-ExchangeOnline.
  2. Now, run the following Exchange Online PowerShell command: 

$BccEmailAddress = @ ("<INSERT-EMAIL>")

$NotifyEmailAddress = @ ("<INSERT-EMAIL>")

Set-HostedOutboundSpamFilterPolicy -Identity Default -
BccSuspiciousOutboundAdditionalRecipients $BccEmailAddress -
BccSuspiciousOutboundMail $true -NotifyOutboundSpam $true -
NotifyOutboundSpamRecipients $NotifyEmailAddress

Monitor:

To verify the Exchange Online Spam Policies are set correctly, use the Microsoft 365 Admin Center:
  1. Go to the Microsoft Admin Center and click Security.
  2. Under Email & collaboration > Policies & rules > Threat policies > Anti-spam policies
  3. Now, select Anti-spam Outbound policy (default).
  4. Verify that Send a copy of outbound messages that exceeds these limits to these users and groups is set to On, after that, make sure the email address is correct.
  5. Verify that Notify these users and groups if a sender is blocked  due to sending outbound spam  is set to On, then ensure that the email address is correct.
To verify that the Exchange Online Spam Policies are set correctly, use the Exchange Online PowerShell Module:
  1. Connect to Exchange Online using Connect-ExchangeOnline.
  2. Now, run the following Exchange Online PowerShell command: 

Get-HostedOutboundSpamFilterPolicy | Select-Object Bcc*, Notify*

      3. Verify both BccSuspiciousOutboundMail and NotifyOutboundSpam are set to True and the email             addresses to be notified are correct.






































Comments

Post a Comment

Popular posts from this blog

Deployment (Part 3)

By Ashwin Venugopal -
Image
  To read part 1, please click  here To read part 2, please click  here Microsoft Monitoring Agent (MMA) MMA is used across multiple Microsoft solutions and has undergone a few name changes as its features and functionality have evolved. If it is being considered to be used, then following areas should be covered during a Microsoft Sentinel deployment project: Consider the timelines and the strategy for a migration to AMA (Azure Monitor Agent) before the MMA end-of-life.  Consider the central deployment and management methodology for MMA. Determine which endpoints are in scope for deployment as these affect the log ingestion volume significantly.  Azure Monitor Agent (AMA) Organizations with MMA as the main Microsoft Sentinel agent should start planning the migration to AMA as soon as possible to avoid a rushed migration. One of the main advantages of AMA is the ability to control the log collection policy centrally and apply different policies against different groups of computers, re
Read more

Project Resourcing (Part 2)

By Ashwin Venugopal -
Image
  To read part 1, please click  here Engineering - SIEM The SIEM engineers configures Microsoft Sentinel, including Log Analytics, Logic Apps, workbooks, and playbooks. They are also responsible for the following high-level tasks: Initial configuration of Azure tenant, including provisioning required resources, assigning access roles, and configuring workspace parameters like log retention, resource tagging, and blueprints.  Deployment and configuration of syslog/CEF log collection agents in appropriate locations to collect logs from on-premises devices. Generally, it will be joint effort of both system engineer and SIEM engineer, involving configuration and potential troubleshooting.  Working with system owners to enable log forwarding and configuring any required parsing of log data in Log Analytics.  Working with security operations to create and deploy KQL analytic rules to offer detections for SOC/Computer Security Incident Response Team (CSRIT) use. Tuning of alert rule parameter
Read more

Design Planning (Part 3)

By Ashwin Venugopal -
Image
  To read part 1, please click  here To read part 2, please click  here Complex Organizational Structures SIEM can be an expensive security control, hence, it is common multiple businesses to contribute to the overall expense. Various organizational units may require a level of access to specific dashboards or sets of data. Microsoft Sentinel offers the ability to assign table-level permissions and limit the level of access to the minimum required to perform requisite job functions.  Role-based Access Control (RBAC) Requirements Microsoft Sentinel offers an extensive list of Azure built-in roles that can be used to provide granular access according to the job requirements and permitted level of access. Some of them are various Microsoft Sentinel dedicated roles: Microsoft Sentinel Contributor- Can perform all engineering-related configuration, such as creating alert rules, configuring data connectors, and additional similar tasks.  Microsoft Sentinel Reader- Can query the log data stor
Read more