SMTP Relay

Establishing an SMTP relay through Microsoft Office 365 requires configuration steps within Office 365 administration, including:

  • Register FMOS / FireMon Security Manager as an application

  • Configure FMOS to relay SMTP through an external server

  • Configure FMOS to relay SMTP through Microsoft 365

  1. Log in to Microsoft Entra using your administrator credentials.

  2. Register FMOS / Security Manager as an application.

    1. In the left pane, click App registrations.

    2. Click New registration.

    3. Enter a name in the Name field,

    4. Select single tenant option in the Supported account types drop-down menu field (the exact name of the “single tenant” option may vary, depending on your instance, but there should be an option that references a “single tenant”)

    5. Leave the Redirect URI field blank. This value is not used in the Client Credentials Flow

    6. Click Register. Entra will create the application and redirect you to the overview page for the new application.

  3. Copy the following values from the new application overview page into a document or other file for safekeeping and save for future use.

    • Application (client) ID

    • Directory (tenant) ID

  4. Create a Client Secret.

    1. Click Certificates & secrets.

    2. Select the Client secrets tab and click New client secret.

    3. In the Add a client secret dialog box, enter a Description, set an Expires time frame from the drop-down menu, and then click Add. When the dialog box closes, you will see the secret in the list of client secrets.

This will be the only opportunity to copy the Client Secret.

  1. Copy the Client Secret.

    1. Use the copy icon to copy the Value field to the clipboard.

    2. Paste the value into a document or other file for safekeeping.

  2. Add API permissions.

    1. Click API permissions > Add a permission.

    2. On the Request API permissions page, click the APIs my organization uses tab.

    3. Use the search bar field to search for Microsoft Graph and click the link.

    4. Click Application permissions.

    5. Use the search bar field to search for Mail. (include the period).

    6. Select the checkboxes to enable the Mail.Read and Mail.Send options.

    7. Click Add permissions.

  3. Grant admin consent.

    1. When you return to the API permissions page, click Grant admin consent for <application name>.

    2. On the Grant admin consent confirmation dialog box, click Yes.

  1. Log in to the FMOS Server Control Panel

  2. On the toolbar menu, click OS > SMTP

  3. In the Configuration Mode drop-down menu, select Relay.

  4. Enable all options in the Conventional SMTP Relay Settings section.

    • SMTP Authentication: enable

    • Relay Port: 25 (default)

    • Relay Auth Username: The user name used to authenticate to the SMTP relay

    • Relay Host: starttls (The host name or IP address of the SMTP relay server)

    • Security Mode: The SMTP security (encryption) method to use when connecting to the relay server.

    • Relay Auth Password: The password used to authenticate to the SMTP server

  5. Click Save Configuration.

  1. Log in to the FMOS Server Control Panel

  2. On the toolbar menu, click OS > SMTP

  3. In the Configuration Mode drop-down menu, select Microsoft365-relay.

  4. Enable all options in the Microsoft 365 Relay Settings section.

    • Microsoft 365 Tenant ID: This is the value saved Step 1 during registration FMOS as an application

    • Microsoft 365 Client Secret: This is the value saved Step 1 during registration FMOS as an application

    • Microsoft 365 Client ID: This is the value saved Step 1 during registration FMOS as an application

  5. Click Save Configuration.