Overview

Typically Mimecast Support will configure Authorized Outbounds for each Mimecast Account during the Implementation Process. Authorized Outbounds provide control over which IP addresses are allowed to send outbound emails to Mimecast, and ensures that unknown mail servers cannot relay off Mimecast Services.

For customers using dynamic IP addressing for outbound emails, a fixed Authorized Outbound cannot be configured. Mimecast therefore requires authentication from the sending mail server to ensure that the connection is validated.

This authentication is configured as part of the SMTP Connector which is created for outbound email delivery from the Exchange Server to Mimecast. For more information about configuring SMTP Connectors, see the following articles below:

 

Before configuring the authentication for your SMTP Connector, a Mimecast local account is required. A new local account can be created or an existing account can be used. For more information on creating a local account on Mimecast, see the full article.

Once the account has been created, the SMTP Connector needs to be amended to configure basic authentication using this account to provide the credentials.

Configuring SMTP Authentication on Exchange 2003 SMTP Connector

  1. Open Exchange System Manager
  2. Scroll down to Connectors, right-click on the Mail Connector, and select Properties
  3. Select the Advanced tab
    SMTP Connector authentication.png
  4. Click the Outbound Security button
  5. Select Basic Authentication
  6. Select Modify
  7. Enter the Mimecast username (full email address) and password using the details of the account created earlier
  8. Click Apply to save changes.

Configuring SMTP Authentication on Exchange 2007/2010 SMTP Connector

  1. Open Exchange Management Console (EMC)
  2. Expand the Organization Configuration
  3. Select Hub Transport
  4. Select the Send Connectors tab in the right-hand viewer
    SMTP Connector Properties.png
  5. Right-click on the existing Mimecast Send Connector, click on the Properties option, and then select the Network tab
  6. Click the Change button to configure Smart host authentication
    SMTP Authentication.png
  7. Select Basic Authentication
  8. Enter the Mimecast username (full email address) and password using the details of the account created earlier
  9. Click OK to save changes
    SMTP Connector authentication details.png

Configuring SMTP Authentication on Exchange 2013 SMTP Connector

Before configuring the authentication for your SMTP Connector, a Mimecast local account is required. A new local account can be created or an existing account can be used. For more information on creating a local account on Mimecast, see the full article.

 

Once the account has been created, the SMTP Connector needs to be amended to configure basic authentication using this account to provide the credentials.

  1. Open Exchange Admin Center (EAC)
  2. Navigate to Mail Flow | Send Connectors
  3. Select the Connector in the list, and click the Edit icon Edit Icon Pencil.png
    Outbound Connector Properties.png
  4. Add two Smart Hosts for your environment, using the Mimecast service addresses provided by our Connect team
    For additional information on Smart Host routing, view the full article: http://technet.microsoft.com/en-us/library/jj673059(v=exchg.150).aspx
  5. For each Smart Host, select the Basic Authentication method, and complete the user account details as configured earlier.
  6. Click the Save button