SQL agent configured to call a SP

All,

My problem scenarion is:

"I have a SQL agent job setup that calls a SP which collects all data and sends a report to some email ids via msdb.dbo.sp_send_dbmail.

The job is scheduled to run daily once around 8:30 PM. Below T-SQL is part of the SP to send the email

exec  msdb.dbo.sp_send_dbmail @recipients=@EMAILID,@blind_copy_recipients=@BCC, 
    @subject = @Subject1 , 
    @body = @body1, 
    @body_format = 'HTML' ; 
END"

Users say that they do receive email on the report but they receive 2 similar emails at the same time.

But the job is scheduled to run only once a day and there is no duplicate job to send email for the same report and to same users.

How do I trouble shoot from where the second email is going?

Regards, Sushant