In most cases, with marketing emails, senders must get permission from their contacts before sending any marketing campaigns to them. Around the world, many countries and regions require this by law.
When you turn on double opt-in for your WooCommerce store subscribers, we send your subscribers an email to confirm their willingness to join your marketing lists. You can then be confident you're sending campaigns to valid, monitored, consenting email addresses.
Before you start
Check out The WooCommerce integration checklist to help track your progress.