Hi All,
Our application calls below Oracle (Oracle APEX) inbuilt package/ procedure to send the emails.
Wwv_Flow_Mail.Send
wwv_flow_mail.push_queue_background.
I have analysed the issue and have found that one of the above procedure (wwv_flow_mail.push_queue_background) is running one of the Oracle APEX job (ORACLE_APEX_MAIL_QUEUE) to send the emails.
I have checked more about the job ORACLE_APEX_MAIL_QUEUE is stopped running for last two days because of which email functions are not working in our application.
I have checked the jobs and i have found that all the APEX jobs are stopped on our database.
Please find the same in screen shot. Could you please help to get the issues fixed
. 
Thanks in advance,
Kiran