http://adprofs.co/beginners-guide-to-gdpr/
https://medium.com/@edagoodman/a-beginners-guide-to-general-data-protection-regulation-gdpr-9d7e847042f2
Couple good sites for info.
You need specific acknowledgement before you can send marketing emails out from EU citizens/residents.
Although, there is enough out there to confuse as well.
EU has tried to allay fears of marketers of small businesses, telling them its focused on big businesses.
There is nothing in the law though that limits the regulations to big businesses only.
Sharick Mirza
Next Gen Post Presort Solutions
Consulting & Analytics
Assurety Consulting Inc
www.assuretyconsulting.com