First, please add your new contacts to your ‘mailing list’ on your contact form setting page (Merchant is responsible to ensure you have permission to send non-support emails to your new contacts and be GDPR compliant).
Second, integrate with Mailchimp etc on your Zotabox dashboard – Email Service Integrations. Mailchimp will ONLY add new emails to your lists (please test with NEW emails only – not previously used or deleted emails).