In your documents view, select "View Fax Status" highlighted in blue at the top of the page. 

Next, select the blue "View" button next to the failed fax you are wanting to resend.

        - This page will allow you to view the status of each of your faxes that have been sent and also see reason for failed fax. 


You will now need to scroll down to the "Fax History" at the bottom right side of the page

If you hover your mouse over the red "Failed" it will highlight blue to "Resend" you will need to click on the "Resend" to send out the fax again.