Exchange 2003: Setting up an SMTP Connector

Document created by user.oxriBaJeN4 Employee on Sep 21, 2015Last modified by user.oxriBaJeN4 Employee on Oct 12, 2016
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One of the Mimecast implementation steps is to direct all outbound email via Mimecast. This requires an SMTP Connector to be configured on your Exchange Server.

Prior to Mimecast accepting outbound emails, the Authorized IP Addresses where emails will be sent from needs to be added to your Mimecast account.

To create the SMTP Connector, follow the steps below:

  1. Open Exchange System Manager (ESM)
  2. If Administrative Groups is displayed, expand the Administrative Groups folder (Otherwise proceed to step 4)
  3. Expand First Administrative Group (or the relevant group if it has been renamed or if there are multiple groups)
  4. If Routing Groups is displayed, expand the Routing Groups folder (Otherwise proceed to step 6)
  5. Expand First Routing Group
  6. Right click Connectors
  7. Select New then SMTP Connector...


  8. Enter a descriptive name for the new connector. For example, Mimecast Connector (1).


  9. Select Forward all mail through this connector...
  10. Enter the Mimecast service address into the Smart Hosts field.


    North America



  11. Under Local Bridgeheads, select the Add... button.
  12. Select the appropriate Exchange server from the list.  This will generally be the Exchange server you are working on. Click the OK button (which will be enabled once a server has been selected):


  13. Click the Apply button to save the SMTP Connector Properties. The result should be similar to the example shown below:

  14. Select the Address Space tab:

  15. Click the Add... button:

  16. Click the OK button
  17. Select SMTP as the Address Type
  18. Keep the default values given:

    Email domain = *
    Cost = 1


  19. Click the OK button twice to complete the creation of your first SMTP connector.


Create a Second SMTP Connector


  1. Repeat steps 6 to 20 using the second Mimecast service address provided
  2. Replace the smart host address with the second service address
  3. Ensure that there are only two SMTP connectors. Exchange will randomly choose between the two connectors, using the same cost route and address space
  4. Delete all other SMTP connectors so only the two pointing to Mimecast remain


The connector is now configured to send all email to the specified smart hosts.

If mail does not start flowing within 60 seconds, restart the SMTP service. To confirm that mail is flowing, send an outbound email to an external email address. Navigate to Accepted Email and refresh until you can see the details of the email you have just sent.

Disabling / Removing Old SMTP Connectors


Disable or remove any other Outbound Send Connectors that were previously used. Failure to do this means your outbound email still uses these older send connectors, and is not routed through Mimecast. Any send connectors used for other purposes (e.g archiving) may still be required to be enabled. If in doubt, consult your Mimecast Support engineer.


Next Step


Once emails are successfully routing outbound through Mimecast, proceed to the next step of the Connect process to configure Recipient Validation and Journaling: