Configure SmarterMail as a Free Gateway Server

This article applies to recent versions of SmarterMail. View articles for SmarterMail 15.x and earlier.

SmarterMail is powerful enough to be used as a complete mail system that performs multiple roles from a single server, including the role of gateway server. In fact, the SmarterMail Free edition can be downloaded and installed to operate as a free gateway server.

Incoming Gateway
Incoming gateways can be utilized to perform spam checks and antivirus scans, host third party antivirus and/or antispam software, and to pre-scan email messages prior to delivery to the primary mail server. Load is also reduced on the primary server as the incoming gateway manages all incoming sessions and performs abuse/intrusion detection.

Follow these steps to configure SmarterMail as an incoming gateway:

  1. Log in to SmarterMail as a system administrator.
  2. Click the Settings icon.
  3. Click Gateways / Failover in the navigation pane.
  4. Click the Incoming tab.
  5. Click New.
  6. In the Options card, select Domain Forward from the Gateway Mode drop down.
  7. Enter the IP address or IP range in the IP Addresses setting.
  8. Verify the Status is set to Enabled.
  9. Type the domain information into the appropriate field on the Domains card.  
  10. If you are using SmarterMail as a gateway to another SmarterMail server, you will also need to follow these steps:
    • Enable the Enable SmarterMail gateway mode toggle on the SmarterMail Gateway card.
    • Type the SmarterMail URL, username, and password used to log into the primary mail server in the appropriate fields.
  11. Click Save.
  12. Next, click Bindings in the navigation pane.
  13. The IP Addresses tab will be shown by default, and a list of IP addresses will load.
  14. Click the desired IP address and add a check next to SMTP.
  15. Click Save.
  16. In DNS, change the MX records of your domains to reference the new gateway server.

Once these steps are completed, install and configure any third-party antivirus or antispam products. All other configuration settings are optional.

Outgoing Gateway
Outgoing gateways can reduce the load on the primary server by using a secondary server to process outgoing mail. One benefit of configuring SmarterMail in this role is that it functions as an effective method to combat blacklisting and can help ensure a quick system recovery.

Follow these steps to configure SmarterMail as an outgoing gateway:

  1. Log in to SmarterMail as a system administrator.
  2. Click the Settings icon.
  3. Click Gateways / Failover in the navigation pane.
  4. The Outgoing tab will be shown by default.
  5. Click New.
  6. Enter the IP address of the outbound gateway, and if applicable, the SMTP Authentication information.
  7. Click Save.
  8. Add the primary mail server's IP address to the IP whitelist for SMTP by following these steps:
    • Click Security in the navigation page.
    • Click the Whitelist tab.
    • Click New in the content pane toolbar.
    • Type the IP address or IP range in the appropriate field(s).
    • Select the SMTP toggle.
    • Click Save.
  9. In your primary mail server's general settings, set the IP address of the gateway server and enable gateway mode. NOTE: If SmarterMail is your primary mail server, these settings can be found at Settings >> Gateways / Failover >> Outgoing Gateways. 

All other configuration settings are optional.

NOTE: To force ALL outgoing email to route through the gateway, including delivery between local domain users, modify the domain's setting for Inbound Message Delivery. If the domain's MX record points to the SmarterMail server, you can simply change the domain's Inbound Message Delivery to "External (use host address)", and specify the gateway. If the domain's MX record points to the gateway, you can change this setting to "External (use MX record)". With the domain marked as being hosted externally, emails between domains users will not be considered a local delivery, ensuring all email is routed through the gateway. 

Learn more about SmarterMail's enterprise email features and benefits.


IMHO you should mention that if admin is using also incoming gateways then it should whitelist outgoing gateways on incoming gateways. Outgoing gateways are returning bounce messages through incoming gateways and in high volume scenario and existing IDS rules for SMTP connections on incoming gateways this bounce messages could trigger blicking of outgoing gateways IP addresses in incoming gateways and this could cause smtp stop from working correctly because of exausting limit of smtp delivery threads (default value 50).

I've experienced this scenario today (it took me few hours to resolve this). Of course separate log file for IDS rules triggering would be also helpfull.

Webio (1/8/2016 at 1:21 PM)