T-SQL: Enable/Disable an Alert
-- Enable an alert.
If Not Exists(Select name From msdb.dbo.sysalerts
Where name = N'yourAlertName')
Exec msdb.dbo.sp_update_alert @name=N'yourAlertName',
@enabled=0
Go
-- Disable an alert.
If Not Exists(Select name From msdb.dbo.sysalerts
Where name = N'yourAlertName')
Exec msdb.dbo.sp_update_alert @name=N'yourAlertName',
@enabled=1
Go