How do I setup a ColdFusion datasource properly for a SQL Server database through Windows Authentication?

At my workplace we are trying to connect to a Microsoft SQL Server database on a different server. Our server is a ColdFusion server that runs the service through a proxy AD account. The owners of the database requested that we create another AD account and have given it access to their database through windows authentication. Upon trying to create the datasource for this connection in the ColdFusion admin page and entering the proxy account's information we receive this error:

Connection verification failed for data source: xxxxxxx java.sql.SQLInvalidAuthorizationSpecException: [Macromedia][SQLServer JDBC Driver][SQLServer]Login failed for user 'xxxxxxx'. The root cause was that: java.sql.SQLInvalidAuthorizationSpecException: [Macromedia][SQLServer JDBC Driver][SQLServer]Login failed for user 'xxxxxx'.

I recognize this is because the connection it was trying to make was probably through SQL Authentication, and that they probably do not have Mixed Authentication settings turned on (based on viewing previous answers).

So my question is, what other steps can we take to setup this connection properly? I'm assuming that on the database side they are not going to be interested in changing their authentication settings or anything, meaning we are stuck with windows authentication only. Do we have any other options?

Solution

This link is old, but the instructions for windows authentication still apply. To set a CF datasource to use windows authentication:

Edit the DSN and select Show Advanced Settings > Connection String. Then enter AuthenticationMethod=Type2 and save.
Leave the username and password fields blank

NB: The ColdFusion service MUST running under the AD account with permissions to the SQL Server. It cannot be changed programmatically.