In SBS 2008, AuthAnvil is unable to send email to external domains


When installing AuthAnvil on an SBS 2008 box allowing Anonymous Users, mail server tests to an external domain fail and the Setup Log shows the SMTP error "Unable to relay 5.7.1"



The AuthAnvil application is not permitted to relay mail messages through exchange 2007.



  1. Open up the Exchange Management Console
  2. Expand Server Configuration
  3. Click Hub Transports
  4. In the "Receive Connectors" tab, right-click on the "Default <servername>" and select Properties. (ie: "Default CONTOSO")
  5. Click the Permission Groups tab
  6. Check Anonymous users

At this point, you will need to grant relay rights to the anonymous user following the configuration for Option 2 described in this Microsoft blog post for Exchange 2007:

The Exchange shell command will look like this:

Get-ReceiveConnector "(AuthAnvil Connector Name)" | Add-ADPermission -User "NT AUTHORITY\ANONYMOUS LOGON" -ExtendedRights "ms-Exch-SMTP-Accept-Any-Recipient"



SBS 2008 servers running any version of AuthAnvil 2FA



If you have any questions or need some help, we would be happy to assist. Open a case at or send an email to

Have more questions?

Contact us

Was this article helpful?
0 out of 0 found this helpful

Provide feedback for the Documentation team!

Browse this section