I have installed your files and everything is good, but I have the below comments:
1- I have a Unicode problem please find the below picture, with Arabic language only, would you please check this problem for me :

2- How can I use "new campaign - Send Delay, sec :
I mean if I want to send around 2500 emails every one hour, what is the number that I need to write?
3- How can I use Mail Sending Settings and Bounce back settings.

4- Why the emails are going to junk mail ?
Waiting your reply please
Many Thanks