Multiple triggers of same Job Quartz.NET

I have the following code:

 IScheduler scheduler = StdSchedulerFactory.GetDefaultScheduler();
            scheduler.Start();
            IJobDetail job = JobBuilder.Create<EmailJob>().StoreDurably().WithIdentity("J_Email", "J_Mailing").Build();         
            ITrigger trigger = TriggerBuilder.Create()
                                .WithIdentity("MailTrigger1", "T_Mail1")
                                .StartNow()                                
                                .WithSimpleSchedule(x => x.WithMisfireHandlingInstructionIgnoreMisfires()
                                    .WithIntervalInSeconds(3)
                                    .RepeatForever())
                                .Build();       


            ITrigger triggernew = TriggerBuilder.Create()
                               .WithIdentity("MailTrigger", "T_Mail")
                               .StartNow()                               
                               .WithSimpleSchedule(x => x.WithMisfireHandlingInstructionIgnoreMisfires()
                                   .WithIntervalInSeconds(5)
                                   .RepeatForever())
                               .Build();        
            scheduler.ScheduleJob(job,triggernew);
            scheduler.ScheduleJob(job,trigger);

I am getting the following exception:

An unhandled exception of type 'Quartz.ObjectAlreadyExistsException' occurred in Quartz.dll

Additional information: Unable to store Job: 'J_Mailing.J_Email', because one already exists with this identification.

But I have been told that you can have multiple triggers of the same JOB. Maybe I am doing something wrong?