Two Similar Sites and One Won't Send Email using Contact Form 7

I am working with two different sites, both on GoDaddy servers, both using the Arras theme for WordPress. On one (my site) I am using it to test plug ins before installing them on the site (not mine) that I am working on. My site, Contact Form 7 works just fine, I’ve made a couple different forms, all send emails to the addresses associated with them. But now that I have installed it on the site that I am working on, and supposed to get paid for, it gives the RED error message “Failed to send your message. Please try later or contact administrator by other way.” I have read that some people have used WP-Mail-SMTP to send a test email and I have tried this plug in and I can not even send a test. I have read through forums on many sites and can not find an answer to my problem. Any suggestions?