Allow me to quote the main part of this link:
What if
Byteball makes a special Discover Byteball page where people can upload their contactlist with email addresses. Every email address you provide will receive 1 MB (± $0,70) via textcoin from this fund.
I see two main problems with this:
1. Basically, it's spamming people. And although that is a powerful method used by almost every social media website, I personally hate it when a company sends me an email because someone else leaked my email address.
2. It will be very easy to abuse. Giveaways in general are heavily abused, and if all that's required is an email address, many people will claim this many times.
I agree with LoyceV. These emails must come from a known trusted sender. It is either a person-to-person email/chat, or a mass mailing from a business/organization you already have some relations with.