Blog
Guides for developers sending email
Practical articles on email APIs, deliverability, domain authentication, and building reliable transactional email systems.
Pricing Comparison
Email API Pricing Comparison 2026: What Every Major Provider Actually Costs
Per-email costs at 1K, 10K, 100K, and 1M sends per month — plus the hidden costs that rarely appear in headline pricing. Covers Amazon SES, SendGrid, Postmark, Mailgun, Resend, Brevo, and tinysend.
Free Tier Comparison
Free Email API: Which Services Actually Give You a Useful Free Tier?
An honest comparison of free email API tiers — monthly limits, daily caps, and what happens when you exceed them. Covers tinysend, SendGrid, Resend, Mailgun, Brevo, Amazon SES, and Postmark.
Deliverability Guide
Email Deliverability: The Complete Guide for Developers (2026)
Why emails land in spam, how inbox providers score senders, and the exact steps to reach the inbox — authentication, sender reputation, IP warming, list hygiene, and bounce handling.
Developer Tutorial
How to Send Email with Ruby: Net::SMTP, Action Mailer, and the API Approach
Net::SMTP for scripts, Action Mailer with Active Job for Rails apps, a REST API call for production services, ERB templates, and a deliverability checklist. With real working code.
Developer Tutorial
How to Send Email with Java: Jakarta Mail, Spring Boot, and the API Approach
Jakarta Mail for direct SMTP, Spring Boot's JavaMailSender with @Async and @Retryable, Thymeleaf templates, and HttpClient for a REST API — with real working code examples.
Developer Tutorial
How to Send Email with C# and .NET: SmtpClient, MailKit, and the API Approach
Why SmtpClient is deprecated, MailKit as the modern SMTP replacement, IHttpClientFactory with Polly retries for the REST API, and Razor email templates. With real working code.
Developer Tutorial
How to Send Email with Go: net/smtp, gomail, and the API Approach
net/smtp for basic scripts, gomail for HTML email and attachments, and a REST API for production services — with context cancellation, idempotency keys, and a retry pattern that fits Go's concurrency model.
Developer Tutorial
How to Send Email with PHP: mail(), PHPMailer, and the API Approach
The mail() function, PHPMailer for SMTP with TLS and HTML email, a REST API with cURL and Guzzle, Laravel and Symfony integration, and a deliverability checklist. With real working code.
Developer Tutorial
How to Send Email with Python: smtplib, requests, and the API Approach
smtplib for scripts, requests for REST API sends, Django and FastAPI integration patterns, error handling with retries, and a deliverability checklist. With real working code.
Developer Guide
How to Send Emails with an API: A Complete Developer Guide
From your first transactional email to drip sequences — everything you need to know about sending email programmatically. Covers picking an API, domain auth, code examples in Node.js and Python, webhooks, and sequences.
Explainer
What is a Transactional Email Service? (And Why Every App Needs One)
Transactional emails are the backbone of every web application. Learn what they are, why you can't use regular email infrastructure at scale, how to choose the right service, and what to actually evaluate beyond marketing claims.
Technical Guide
DKIM, SPF, and DMARC: Complete Email Authentication Setup Guide
The definitive guide to authenticating your email domain — with exact DNS records, troubleshooting tips, DMARC rollout sequence, and what to do when your emails still land in spam after authentication.
Developer Tutorial
How to Send Email in Node.js: A Practical Guide with Code
From a basic Nodemailer setup to a production-grade email API — error handling, HTML templates with variables, onboarding sequences, and a deliverability checklist before you launch.
Technical Guide
SMTP vs Email API: Which Should You Use?
The real differences between SMTP and REST email APIs — connection management, error handling, webhooks, serverless compatibility — with Node.js code comparing Nodemailer to a fetch-based API call.
Growth Engineering
Email Sequences for SaaS Onboarding: What to Send and How to Build It
The 5-email onboarding framework — timing, behavioral stop conditions, and the code to automate it. Includes activation triggers, unsubscribe handling, and what metrics actually matter.
AI Agents
Email API for AI Agents: Integration Guide
How Claude Code, Cursor, and Codex can send email — MCP server setup, idempotency keys to prevent duplicate sends, Node.js and Python examples, and how major email APIs compare for agentic workflows.
Comparison
Best Email APIs for Developers in 2026
Amazon SES, SendGrid, Postmark, Resend, and tinysend compared side by side — pricing, deliverability, API quality, and which one to pick for your use case.