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1. Right-click a SQL Server instance in the Servers tree.
2. Select Configure Alerts.
3. Select the Days since last backup metric in the Alert Configuration window.
4. If the metric features a per-database, on the Configuration tab of the Alert Configuration window, click Add. Use the drop-down list to select the database to which you want to apply these settings. 
5. Check the boxes next to Informational, Warning, and Critical to include alerts for these states.
6. Change the alert thresholds by moving the arrows to the appropriate levels or by double-clicking the value and typing a new threshold level.
7. Click Advanced to apply alert suppression.
8. Click OK to accept your changes.

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