David Finger and Alexander Zeh discuss best practices for email deliverability. They recommend obtaining subscriber consent through a double opt-in process and making unsubscribes easy to process immediately. Additionally, they suggest implementing list-unsubscribe and RFC 8058, monitoring feedback loops from email providers, ensuring SPF, DKIM and DMARC are configured correctly, avoiding overly promotional emails, and keeping an eye on future standards like BIMI and email markup.