How to troubleshoot Advanced Reporting Subscriptions in SQL Server Reporting Services. E-mail Failures.
When E-Mail subscriptions are set up in Advanced Reporting, they can stop sending if the email server used has been changed or if server not reachable. When you check your subscriptions, you will see failure statuses.
In some cases, the problem can be caused by the currently configured email server may have been decommisioned the new server not configured. To check and change if needed, you would do that in SQL Server Reporting Services (SSRS) Configuration Manager.
1 Open SQL Server Reporting Services Configuration Manager
2 Connect to the server when prompted
3 Click the E-Mail Settings link on right side of window.
4 Make any change to the SMTP server that was made by entering new or correct SMTP server address.
5 Click apply to save change. You shouldn't have to make any changes to individual subscriptions.
Once you save changes, the next time the subscriptions are scheduled, they should run normally and you subscription status should show successful run statuses.