A few years ago I had a site that would send free sms but then it stopped working. I don't think you can send 700,000 sms for free, but there are some cheap sites out there.
No. The telephone company will know that it's spam when you send 100s of messages in a short time even if you change name of receiver.I don't have opt-ins, only a list of professionals I'm marketing to. Its completely relevant to their profession. If I customize each text message to include their name and make it seem personal and not spam, would that pass?