Campaigns in Dev/UAT not sending emails

Hello,

I've sent emails in our Prod system but we are exploring new avenues and using Dev/UAT for testing. The emails aren't going out. I set it up the same way as I did when I successfully sent emails in Prod. Here are some screenshots if anyone has any ideas of potential issues. 

I am confused as to why it says "Ready to send" instead of "sent." Not sure if that is the source of the problem.

I really appreciate everyone's help!

Matt