This looks like you're unable to send email, in most cases this is related to the fact that AWS blocks port 25 until you request it be opened. Another issue you may want to look at if your emails are being rejected is How to Keep Your Email Out of the Spam Folder | cPanel & WHM Documentation
As @cPanelLauren says. You have to request them to open port 25. If they do not allow you to send mail at all, you might need to find an alternative, I have no idea of an alternative. I have this same problem with my ISP LOL