How to Configure IIS SMTP Server to relay with authentication

The following KB article describes how to use Microsoft’s SMTP engine in IIS.  It is intended to lay out guidelines for how to send email off your existing externally hosted email server.  You will need to obtain the following email settings before this can be setup.  Your mail server may require certain encryption settings that the SMTP service will not work with.  You should contact your mail provider for assistance with the following information.

–          Your company specific outbound email server (for example

–          Your company specific outbound email account (for example

–          Your company specific outbound email password (for example eclmail123)

–          Your company specific outbound email port (usually tcp port 25 by default).

Screenshots below are for illustration purposes only and should be used as en example.

Install the SMTP Service

  • Click Start
  • Go to Server Manager
  • Click Features
  • Select Add Features
  • Select SMTP Server and continue through wizard

Configure the SMTP Service

  • Go to Start
  • Select Internet Information Services (IIS) 6.0 Manager
  • Right-click on SMTP Virtual Server #1
  • Select Properties
    • Click on the Access tab
    • Click on Relay – add your local network, then select OK
  • Click on the Delivery tab
    • Click on Outbound security…
      • Under Basic authentication, enter your outbound username and password for your email account and click OK (this information may vary based on your mail servers requirements).
    • Click On Advanced…
      • Fill in Fully-qualified domain name
      • Set Smart host to the main SMTP server’s address
      • Masquerade domain (optional)
      • Click OK
    • Click on Outbound connections… (optional)
      •  Only select this option If your outbound port needs to be adjusted from port 25 (you will need to ask your email provider). 
      • Click OK