---
title: How do I setup Microsoft 365 as a Domain Mail Server in SecurityGateway?
description: Follow the steps below to add a Microsoft 365 server as a Domain Mail server in SecurityGateway.
---

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# How do I setup Microsoft 365 as a Domain Mail Server in SecurityGateway?

## Follow the steps below to add a Microsoft 365 server as a Domain Mail server in SecurityGateway.

1. Log into SecurityGateway
2. Select **Setup/Users**
3. Select **Mail Configuration**
4. Select **Domain Mail Servers**
5. Click **New**
6. In the **Properties** section, enter the Domain Mail Server description
7. For the host name, follow the example below 
     - If the Microsoft 365 domain is domain.com use the following; 
           - domain-com.mail.protection.outlook.com
8. Enter the port number for SMTP connections (default 25)
9. Select **Required SMTP Authentication** if required and enter the Username and Password
10. In the **Type** section, click **This server is a default mail server** if true 
      - Any other defined domains in SecurityGateway that do not have a defined domain mail server will use this server to route mail.
11. Use the **Available/Selected Domains** list to attach a defined domain to a domain mail server.  
    ![security\_gateway\_office\_365\_domain](https://knowledge.mdaemon.com/hs-fs/hubfs/KBAs/security_gateway_office_365_domain.png?width=632&name=security_gateway_office_365_domain.png)
12. Click **Save and Close**

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