It is very important to follow the laws that apply to the country (or region) you are sending email to as the ones that your email provider is complying to. Please check in its Terms of Use and/or Anti-Spam Policy.
Canada: You must abide by Canada’s Bill C-28 (CASL)- CASL: What every marketer needs to know.
USA: You need to comply with US CAN-SPAM.
European Union has written the General Data Protection Regulation (GDPR) that many member countries use either as a basis for their own laws or in lieu of a formal law.
Here are the links to their websites for complete information:
United States The CAN-SPAM Act: Requirements for Commercial Emailers
Canada Canada’s anti-spam legislation (CASL)
European Union General Data Protection Regulation (GDPR)
Australia Spam Act 2003