User unable to SSO to Salesforce.com
Issue
The user is unable to sign-in to his SalesForce account via SecureAuth SSO
Note
Salesforce Error Message
Login Error...Your login attempt using single sign-on with an identity provider certificate has failed. Please contact your salesforce.com administrator for more information.
Solution
Ensure the user's Salesforce.com ID is defined in user AD profile for mapping (email1, email2,..)