August 2023 Summaries

SPF (Sender Policy Framework) is an email authentication protocol that helps inboxes filter out unwanted emails by verifying the sender's domain. It declares a list of allowed origins, and if an email doesn't match, it's considered spam. A domain or subdomain can only have one SPF policy, which is usually set in a TXT record. Inboxes look at the Return-Path to confirm the message's legitimacy. Once passed, a vetting process begins with DKIM (DomainKeys Identified Mail), which adds a signature to verify the email sender's identity using a private/public key pairing. If an email fails SPF or DKIM, DMARC (Domain-based Message Authentication, Reporting & Conformance) sets rules for handling such cases, and implementing it enhances a domain's reputation by preventing suspicious messages from being delivered. BIMI (Brand Indicators for Message Identification) is another way to stand out in the inbox by showcasing a brand's legitimacy through logo display and verified checkmarks, but obtaining it requires an exclusive verification process.

Supabase Auth allows users to send emails, but these emails are typically sent from `[email protected]`, which may not be suitable for production use. To improve deliverability and brand recognition, it's recommended to set up a custom SMTP server. Supabase has made it easy to configure such a server, with an integration available with Resend that allows users to connect their project and send emails from their own domain. This setup provides full control and visibility over email delivery, enabling users to see if emails were sent, delivered, bounced, or marked as spam. Users can also manually configure their SMTP server by navigating to Project Settings and Auth, where they can input the necessary settings, such as host, port number, username, password, sender email, and sender name.

The support of modern technologies like React for email building and Serverless for sending emails is crucial to make email feel like the web. A 40-year-old protocol, SMTP, still remains a standard protocol underlying the 347 billion emails sent every day due to its provider agnosticism, allowing integrations to be based on the protocol rather than a specific email API. This has led to the realization that SMTP is not something to avoid but rather something to embrace for legacy systems and modern frameworks alike, enabling quick and standardized ways for customers to send emails.