Blocking notification alert job

Step  1:  : Create below procedure in msdb database

use msdb
go
IF  EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].[usp_Blocking_Notification]') AND type in (N'P', N'PC'))
DROP PROCEDURE [dbo].[usp_Blocking_Notification]
GO
/*

exec usp_Blocking_Notification 'venkateswara.sangu@gmail.com',500000

change DBMail profile & From address in below procedure before creating
*/

CREATE PROCEDURE usp_Blocking_Notification   @Receipiant nvarchar(30),@waittime int = 100000
AS
SELECT s.session_id
    ,r.STATUS
    ,r.blocking_session_id
    ,r.wait_type
    ,wait_resource
    ,r.wait_time / (1000.0) 'WaitSec'
    ,r.cpu_time
    ,r.logical_reads
    ,r.reads
    ,r.writes
    ,r.total_elapsed_time / (1000.0) 'ElapsSec'
    ,Substring(st.TEXT, (r.statement_start_offset / 2) + 1, (
            (
                CASE r.statement_end_offset
                    WHEN - 1
                        THEN Datalength(st.TEXT)
                    ELSE r.statement_end_offset
                    END - r.statement_start_offset
                ) / 2
            ) + 1) AS statement_text
    ,Coalesce(Quotename(Db_name(st.dbid)) + N'.' + Quotename(Object_schema_name(st.objectid, st.dbid)) + N'.' + Quotename(Object_name(st.objectid, st.dbid)), '') AS command_text
    ,r.command
    ,s.login_name
    ,s.host_name
    ,s.program_name
    ,s.host_process_id
    ,s.last_request_end_time
    ,s.login_time
    ,r.open_transaction_count
INTO #temp_requests
FROM sys.dm_exec_sessions AS s
INNER JOIN sys.dm_exec_requests AS r ON r.session_id = s.session_id
CROSS APPLY sys.dm_exec_sql_text(r.sql_handle) AS st
WHERE r.session_id != @@SPID and
r.wait_time > @waittime
ORDER BY r.cpu_time DESC
    ,r.STATUS
    ,r.blocking_session_id
    ,s.session_id

IF (
        SELECT count(*)
        FROM #temp_requests
        WHERE blocking_session_id > 50
        ) <> 0
BEGIN
    -- blocking found, sent email.
    DECLARE @tableHTML NVARCHAR(MAX);

    SET @tableHTML = N'<H1>Blocking Report</H1>' + N'<table border="1">' + N'<tr>' + N'<th>session_id</th>' + N'<th>Status</th>' +
                     N'<th>blocking_session_id</th><th>wait_type</th><th>wait_resource</th>' +
                     N'<th>WaitSec</th>' + N'<th>cpu_time</th>' +
                     N'<th>logical_reads</th>' + N'<th>reads</th>' +
                     N'<th>writes</th>' + N'<th>ElapsSec</th>' + N'<th>statement_text</th>' + N'<th>command_text</th>' +
                     N'<th>command</th>' + N'<th>login_name</th>' + N'<th>host_name</th>' + N'<th>program_name</th>' +
                     N'<th>host_process_id</th>' + N'<th>last_request_end_time</th>' + N'<th>login_time</th>' +
                     N'<th>open_transaction_count</th>' + '</tr>' + CAST((
                SELECT td = s.session_id
                    ,''
                    ,td = r.STATUS
                    ,''
                    ,td = r.blocking_session_id
                    ,''
                    ,td = r.wait_type
                    ,''
                    ,td = wait_resource
                    ,''
                    ,td = r.wait_time / (1000.0)
                    ,''
                    ,td = r.cpu_time
                    ,''
                    ,td = r.logical_reads
                    ,''
                    ,td = r.reads
                    ,''
                    ,td = r.writes
                    ,''
                    ,td = r.total_elapsed_time / (1000.0)
                    ,''
                    ,td = Substring(st.TEXT, (r.statement_start_offset / 2) + 1, (
                            (
                                CASE r.statement_end_offset
                                    WHEN - 1
                                        THEN Datalength(st.TEXT)
                                    ELSE r.statement_end_offset
                                    END - r.statement_start_offset
                                ) / 2
                            ) + 1)
                    ,''
                    ,td = Coalesce(Quotename(Db_name(st.dbid)) + N'.' + Quotename(Object_schema_name(st.objectid, st.dbid)) +
                        N'.' + Quotename(Object_name(st.objectid, st.dbid)), '')
                    ,''
                    ,td = r.command
                    ,''
                    ,td = s.login_name
                    ,''
                    ,td = s.host_name
                    ,''
                    ,td = s.program_name
                    ,''
                    ,td = s.host_process_id
                    ,''
                    ,td = s.last_request_end_time
                    ,''
                    ,td = s.login_time
                    ,''
                    ,td = r.open_transaction_count
                FROM sys.dm_exec_sessions AS s
                INNER JOIN sys.dm_exec_requests AS r ON r.session_id = s.session_id
                CROSS APPLY sys.dm_exec_sql_text(r.sql_handle) AS st
                WHERE r.session_id != @@SPID
                    AND blocking_session_id > 0
                ORDER BY r.cpu_time DESC
                    ,r.STATUS
                    ,r.blocking_session_id
                    ,s.session_id
                FOR XML PATH('tr')
                    ,TYPE
                ) AS NVARCHAR(MAX)) + N'</table>';

    EXEC msdb.dbo.sp_send_dbmail @body = @tableHTML
,@from_address  = 'DevDBAAdmin@techridesol.com'
        ,@body_format = 'HTML'
        ,@profile_name = N'TechRideSolDBMail'
        ,@recipients = @Receipiant
        ,@Subject = N'Blocking Detected'
END

DROP TABLE #temp_requests


Step  2 : 

Connect to SQL Server using SSMS and Expand SQL Server Agent and right click on Jobs and select New Job

In New Job window provide the job name and owner as SA and select Steps Tab in left side pane 

In Job Steps Window click on NEW button to create a job step