When you are logged into Fiitfu, you can go to the "MESSAGES" tab  (through the menu icon of 3 horizontal lines in the upper right corner of the screen) and here you will be able to see your Sent Messages as well as your Scheduled Messages.  

You will see if a message has been Scheduled / Queued / Sent 

Click on the blue subject line of your email for Sent Messages, and you can see here if  and when your email has been delivered, viewed or clicked on.