Tutorial: Azure AD SSO integration with Mimecast - Microsoft Entra (2024)

In this tutorial, you'll learn how to integrate Mimecast with Azure Active Directory (Azure AD). When you integrate Mimecast with Azure AD, you can:

• Control in Azure AD who has access to Mimecast.
• Enable your users to be automatically signed-in to Mimecast with their Azure AD accounts.
• Manage your accounts in one central location - the Azure portal.

Prerequisites

To get started, you need the following items:

• An Azure AD subscription. If you don't have a subscription, you can get a free account.
• Mimecast single sign-on (SSO) enabled subscription.

Scenario description

In this tutorial, you configure and test Azure AD SSO in a test environment.

• Mimecast supports SP and IDP initiated SSO.

Add Mimecast from the gallery

To configure the integration of Mimecast into Azure AD, you need to add Mimecast from the gallery to your list of managed SaaS apps.

1. Sign in to the Azure portal using either a work or school account, or a personal Microsoft account.
2. On the left navigation pane, select the Azure Active Directory service.
3. Navigate to Enterprise Applications and then select All Applications.
4. To add new application, select New application.
5. In the Add from the gallery section, type Mimecast in the search box.
6. Select Mimecast from results panel and then add the app. Wait a few seconds while the app is added to your tenant.

Alternatively, you can also use the Enterprise App Configuration Wizard. In this wizard, you can add an application to your tenant, add users/groups to the app, assign roles, as well as walk through the SSO configuration as well. Learn more about Microsoft 365 wizards.

Configure and test Azure AD SSO for Mimecast

Configure and test Azure AD SSO with Mimecast using a test user called B.Simon. For SSO to work, you need to establish a link relationship between an Azure AD user and the related user in Mimecast.

To configure and test Azure AD SSO with Mimecast, perform the following steps:

1. Configure Azure AD SSO - to enable your users to use this feature.
   1. Create an Azure AD test user - to test Azure AD single sign-on with B.Simon.
   2. Assign the Azure AD test user - to enable B.Simon to use Azure AD single sign-on.
2. Configure Mimecast SSO - to configure the single sign-on settings on application side.
   1. Create Mimecast test user - to have a counterpart of B.Simon in Mimecast that is linked to the Azure AD representation of user.
3. Test SSO - to verify whether the configuration works.

Configure Azure AD SSO

Follow these steps to enable Azure AD SSO in the Azure portal.

1. In the Azure portal, on the Mimecast application integration page, find the Manage section and select single sign-on.

2. On the Select a single sign-on method page, select SAML.

3. On the Set up single sign-on with SAML page, click the pencil icon for Basic SAML Configuration to edit the settings.

   

4. On the Basic SAML Configuration section, if you wish to configure the application in IDP initiated mode, perform the following steps:

   a. In the Identifier textbox, type a URL using one of the following patterns:

   Region	Value
   Europe	https://eu-api.mimecast.com/sso/<accountcode>
   United States	https://us-api.mimecast.com/sso/<accountcode>
   South Africa	https://za-api.mimecast.com/sso/<accountcode>
   Australia	https://au-api.mimecast.com/sso/<accountcode>
   Offshore	https://jer-api.mimecast.com/sso/<accountcode>

   Note

   You will find the accountcode value in the Mimecast under Account > Settings > Account Code. Append the accountcode to the Identifier.

   b. In the Reply URL textbox, type one of the following URLs:

   Region	Value
   Europe	https://eu-api.mimecast.com/login/saml
   United States	https://us-api.mimecast.com/login/saml
   South Africa	https://za-api.mimecast.com/login/saml
   Australia	https://au-api.mimecast.com/login/saml
   Offshore	https://jer-api.mimecast.com/login/saml

5. If you wish to configure the application in SP initiated mode:

   In the Sign-on URL textbox, type one of the following URLs:

   Region	Value
   Europe	https://eu-api.mimecast.com/login/saml
   United States	https://us-api.mimecast.com/login/saml
   South Africa	https://za-api.mimecast.com/login/saml
   Australia	https://au-api.mimecast.com/login/saml
   Offshore	https://jer-api.mimecast.com/login/saml

6. Click Save.

7. On the Set up single sign-on with SAML page, In the SAML Signing Certificate section, click copy button to copy App Federation Metadata Url and save it on your computer.

   

Create an Azure AD test user

In this section, you'll create a test user in the Azure portal called B.Simon.

1. From the left pane in the Azure portal, select Azure Active Directory, select Users, and then select All users.
2. Select New user at the top of the screen.
3. In the User properties, follow these steps:
   1. In the Name field, enter B.Simon.
   2. In the User name field, enter the username@companydomain.extension. For example, B.Simon@contoso.com.
   3. Select the Show password check box, and then write down the value that's displayed in the Password box.
   4. Click Create.

Assign the Azure AD test user

In this section, you'll enable B.Simon to use Azure single sign-on by granting access to Mimecast .

1. In the Azure portal, select Enterprise Applications, and then select All applications.
2. In the applications list, select Mimecast.
3. In the app's overview page, find the Manage section and select Users and groups.
4. Select Add user, then select Users and groups in the Add Assignment dialog.
5. In the Users and groups dialog, select B.Simon from the Users list, then click the Select button at the bottom of the screen.
6. If you are expecting a role to be assigned to the users, you can select it from the Select a role dropdown. If no role has been set up for this app, you see "Default Access" role selected.
7. In the Add Assignment dialog, click the Assign button.

Configure Mimecast SSO

1. In a different web browser window, sign into Mimecast Administration Console.

2. Navigate to Administration > Services > Applications.

   

3. Click Authentication Profiles tab.

   

4. Click New Authentication Profile tab.

   

5. Provide a valid description in the Description textbox and select Enforce SAML Authentication for Mimecast checkbox.

   

6. On the SAML Configuration for Mimecast page, perform the following steps:

   

   a. For Provider, select Azure Active Directory from the Dropdown.

   b. In the Metadata URL textbox, paste the App Federation Metadata URL value, which you have copied from the Azure portal.

   c. Click Import. After importing the Metadata URL, the fields will be populated automatically, no need to perform any action on these fields.

   d. Make sure you uncheck Use Password protected Context and Use Integrated Authentication Context checkboxes.

   e. Click Save.

Create Mimecast test user

1. In a different web browser window, sign into Mimecast Administration Console.

2. Navigate to Administration > Directories > Internal Directories.

   

3. Select on your domain, if the domain is mentioned below, otherwise please create a new domain by clicking on the New Domain.

   

4. Click New Address tab.

   

5. Provide the required user information on the following page:

   

   a. In the Email Address textbox, enter the email address of the user like B.Simon@yourdomainname.com.

   b. In the Global Name textbox, enter the Full name of the user.

   c. In the Password and Confirm Password textboxes, enter the password of the user.

   d. Select Force Change at Login checkbox.

   e. Click Save.

   f. To assign roles to the user, click on Role Edit and assign the required role to user as per your organization requirement.

   

Test SSO

In this section, you test your Azure AD single sign-on configuration with following options.

SP initiated:

• Click on Test this application in Azure portal. This will redirect to Mimecast Sign on URL where you can initiate the login flow.

• Go to Mimecast Sign-on URL directly and initiate the login flow from there.

IDP initiated:

• Click on Test this application in Azure portal and you should be automatically signed in to the Mimecast for which you set up the SSO.

You can also use Microsoft My Apps to test the application in any mode. When you click the Mimecast tile in the My Apps, if configured in SP mode you would be redirected to the application sign on page for initiating the login flow and if configured in IDP mode, you should be automatically signed in to the Mimecast for which you set up the SSO. For more information about the My Apps, see Introduction to the My Apps.

Next steps

Once you configure Mimecast you can enforce session control, which protects exfiltration and infiltration of your organization’s sensitive data in real time. Session control extends from Conditional Access. Learn how to enforce session control with Microsoft Defender for Cloud Apps.