Email remains a critical component of business communication, with over 300 billion emails sent daily, highlighting the importance of email deliverability tools. Recent updates from major providers like Google and Yahoo, implementing stricter policies to combat spam, have made email deliverability a significant concern for businesses. Developers must understand the distinction between transactional and contextual emails, with APIs providing robust solutions for enhancing deliverability and engagement. Email APIs facilitate integration with preferred email services, support authentication protocols, and offer tools for managing unsubscribes, bounces, and analytics, ensuring compliance with regulations like GDPR and CAN-SPAM. Several email deliverability tools, such as Nylas, Twilio SendGrid, Mailgun, and Amazon SES, offer features like spam filter testing, bounce management, and reputation monitoring, each catering to different needs and budgets. Nylas stands out for its comprehensive capabilities, including nearly 100% email deliverability, advanced analytics, and seamless integration, making it an ideal choice for developers seeking reliable and efficient email solutions.