CREATE TRIGGER delUsers ON db_users AFTER DELETE
AS
BEGIN
SET NOCOUNT ON
Declare
@User_name varchar(100),
@body varchar(100)
Select @User_name=usrname from deleted
Set @body='User ' +@User_name+ ' Deleted'
EXEC msdb.dbo.sp_send_dbmail
@profile_name = 'Mail Profile 1',
@recipients = 'me@email.co.uk',
@body = @body,
@subject ='User Deletion'
END
--Where usrname is the field in your table db_users
..