It’s against the CAN-SPAM rules to send emails to consumers who have not opted in to receive information from a company. It’s also against the CAN-SPAM rules for a list provider to sell someone a list of email addresses.
However, it is legal for a list supplier to deploy an email for a company to a list of opt-in emails. These emails usually come from forms where you sign up for something and you check a box that says “You would like to receive promotional emails from our partners”. Only about 15 – 20% of consumers opt into these so it’s not a lot of coverage.
You will get a high SPAM rate if you do this, which drives down your reputation, which lowers deliverability rates – worse yet, ISP’s blacklist you because they see a lot of SPAM coming from your IP address.
Finally, Our SendGrid account is not set up for mass emails and it’s not included in the $20/month.
For more information, please visit the Federal Trade Commission Website