Our friends at Postmark have highlighted the importance of keeping email secure, noting that standard SMTP methods are vulnerable to plain text content. To address this, they use opportunistic TLS for outbound emails and almost force DKIM (DomainKeys Identified Mail) for new sending addresses, achieving a 91% adoption rate among customers. Additionally, Postmark offers a free DMARC tool to monitor and implement DMARC protection for email sent on behalf of the sender, with plans to add more security features to their application and API endpoints in the future.