Why is deadlock alert not working?

I created a deadlock alert including notification to an operator like this:

EXEC msdb.dbo.sp_add_alert @name=N'1205 Deadlock', 
        @message_id=1205, 
        @severity=0, 
        @enabled=1, 
        @delay_between_responses=30, 
        @include_event_description_in=1, 
        @database_name=N'myDB', 
        @category_name=N'[Uncategorized]', 
        @job_id=N'00000000-0000-0000-0000-000000000000';

This alert is registered for notification.

It's history says it never appeared although it is in place for months and there are multiple deadlocks per day. I created a deadlock manually. It shows up in the Log File.

What is missing for this alert to raise a notification?
Other notifications like e.g. 18456 Invalid Login work fine.

Probably the error 1205 is not set up to be logged in ERRORLOG. Look it up in sys.messages:

SELECT *
FROM sys.messages 
WHERE message_id = 1205;

If the column is_event_logged is set to 0, change it this way:

EXEC master.sys.sp_altermessage 
    @message_id = 1205,
    @parameter = 'WITH_LOG',
    @parameter_value = 'true';

The documentation for sp_add_alert describes under which conditions an alert is raised:

Remarks


sp_add_alert must be run from the msdb database.


These are the circumstances under which errors/messages generated by SQL Server and SQL Server applications are sent to the Windows application log and can therefore raise alerts:

• Severity 19 or higher sys.messages errors

• Any RAISERROR statement invoked with WITH LOG syntax

• Any sys.messages error modified or created using sp_altermessage

• Any event logged using xp_logevent

StackExchange Database Administrators Q#132495, answer score: 8