SSRS 2008 R2 Subscriptions not sending

All -

I have recently upgraded our production environment from Sql Server Reporting Services 2005 to 2008 R2. Along with the upgrade, I have configured SSRS with Forms Based Authentication and have successfully set up all parts of Reporting Services except for one thing, the subscriptions are failing.

Important things to keep in mind:

1. I have pulled the Report Server Databases over from the old environment, and restored the key, so I know that the information can be read.
2. The emails WILL send if the subscription is set up to send only a link to the report. (So this leads me to believe that the SMTP configuration is correct).
3. All reports work when being accessed from the application tied to Reporting Services.
4. We have already tried updating the Unattended Execution Account, but it made no change.
5. I have verified that the SQL Browser Service is running and the firewall has exceptions for SQL Browswer and for port 1434.

Any ideas or help on this matter would be greatly appreciated. We have been working on this problem for a few days now and we would like to have this completed ASAP.

The error that is generated in the error log is:

ERROR: Error sending email. Microsoft.ReportingServices.Diagnostics.Utilities.RSException: An error occurred when invoking the authorization extension. ---> Microsoft.ReportingServices.Diagnostics.Utilities.AuthorizationExtensionException: An error occurred when invoking the authorization extension. ---> System.Web.HttpException: Unable开发者_StackOverflow社区 to connect to SQL Server database. ---> System.Data.SqlClient.SqlException: A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: SQL Network Interfaces, error: 26 - Error Locating Server/Instance Specified)

Ok everyone, a lot of playing around, I was able to come up with a work-around. Granted, this is not the overall solution, but it DOES solve our problem.

After digging through the custom security DLL, I noticed that an exception was generated in the CheckAccess() method for Report Operations in the Authorization class. I decided to hardwire it to "True" to get past it and see where it would lead me. Success! There are of course some security risks involved with this fix, but our current environment hides the report server behind our firewall and every employee logged in is authorized to see the reports.

There are several CheckAccess() methods in here to limit access to certain aspects of Reporting Services and I only needed to open up the Report Operations.