Go back to basics. Put yourself in your prospect's shoes.
How do you react to unsolicited emails ? How about emails from someone you don't know and have never heard from before ?
If your goal is to make a bad impression, an unsolicited email blast is one of the quickest ways to achieve it.
Over sharing with Twitter, and poorly conceived social media content can easily taint your reputation. And bad news travels fast.
There are also further complications for projects within Australia. Opt-in permission is now mandated for all direct marketing activities by the Australian Federal Government. Legislation exists to cover email and SMS marketing, as well as the privacy of individuals.
The consequences of making a mistake can be very damaging.