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Practical guides for sending reliable transactional email.

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/6 min readdomainsdnscloudflare

One approval instead of five DNS records: Domain Connect on SMTPfast

If your domain is on Cloudflare, SMTPfast can publish its sending records, and separately the inbound MX, through Domain Connect. You review each set on Cloudflare's screen, approve, and the records are written for you. Here is how it works, what gets written, and what to do when your DNS lives elsewhere.

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/5 min read

Logs API and webhook deliveries: answer 'did it send?' without opening the dashboard

Two additions for the debugging side of email: the event log behind the Logs page is now an API, and every webhook has a delivery log with attempts, responses, automatic retries and a retry button.

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/4 min read

Inbound email: receive mail on your domain, read it through the API

SMTPfast now receives email on your verified domains. Enable it per domain, publish one MX record, and mail for any address on that domain reaches your Inbound page, the receiving API and an email.received webhook.

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/3 min read

How SMTPfast Uses AI to Keep Bad Actors Off the Platform

Applications for sending access are now researched and risk-scored by an AI system built on DigitalOcean's AI platform, so humans make the final call with the evidence already gathered. Here is how it works and why it matters for everyone sending through the platform.

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/5 min read

Feedletter: Turn an RSS Feed or Markdown Folder into a Newsletter

A free, open-source CLI and browser studio that reads your RSS feed or Markdown content, lets you curate and preview the issue, and sends it with SMTPfast. Per-recipient unsubscribe, history so nothing goes out twice, and a GitHub Action for hands-off sends.

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/5 min read

Manage SMTPfast as Code with the Terraform Provider

Register sending domains, publish DKIM/SPF/DMARC records, mint API keys, and wire up webhooks from Terraform. Reproducible email infrastructure, reviewed in a pull request instead of clicked together in a dashboard.

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/7 min read

The Boring Stack Behind SMTPfast (And Why Boring Is Reliable)

SMTPfast runs on a deliberately small stack: a Next.js app, Postgres, a Redis queue, a worker, and Amazon SES. Here is the whole architecture, and why fewer moving parts is exactly what makes your email arrive.

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/3 min read

Teams in SMTPfast: shared workspaces, roles, and invites

Bring your teammates and clients into one workspace. Shared domains, contacts, and API keys, with roles that keep billing and member management where they belong.

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/5 min read

Prepaid Email Credits for SMTPfast

Buy optional overflow email credits for traffic spikes without changing your monthly plan. Your plan allowance is used first, then credits cover extra accepted emails.

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/5 min read

Auto-welcome email on every signup form

Every SMTPfast signup form can now send a welcome email the moment a subscriber confirms. Two text fields and a save. Welcome emails open at 50-70% on a typical SaaS list, against 15-32% for broadcasts.

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/6 min read

Broadcast Campaigns in SMTPfast

Broadcasts let you send product updates and newsletters to subscribed contacts with drafts, tests, scheduling, suppression checks, and delivery metrics.

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/13 min read

Best Email API in 2026: An Engineer's Honest Comparison

Eight transactional email APIs ranked by what matters: developer experience, pricing, deliverability, and where each one breaks. Code samples for every one.

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/4 min read

Live Tail: real-time email event logs in your dashboard

Watch every send, delivery, bounce, open, and click stream into your dashboard in real time. tail -f for email.

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/5 min read

Add a signup form to your website in 5 minutes

Drop a form on your site, collect contacts straight into SMTPfast, with double opt-in and webhook events out of the box.

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/5 min read

API Key Security: Best Practices for Email APIs

A leaked API key can send thousands of emails on your behalf in minutes. Here is how to keep your keys safe.

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/5 min read

DKIM, SPF, and DMARC Explained: The Complete Guide

Three DNS records stand between your emails and the spam folder. Here is what each one does and exactly how to set them up.

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/6 min read

How to Build and Protect Your Email Sender Reputation

Your sender reputation determines whether emails reach the inbox or land in spam. Here is how to build it from scratch and keep it healthy.

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/5 min read

Mailgun vs SMTPfast: Developer Email API Comparison

Mailgun has been a developer favorite for years. SMTPfast is the new challenger. Here is how they stack up on DX, pricing, and features.

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/5 min read

How to Migrate from SendGrid to SMTPfast

A step-by-step guide to moving your transactional email from SendGrid to SMTPfast. Includes code before and after for every language.

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/4 min read

Send Emails from Node.js in 5 Minutes with SMTPfast

No SDK, no dependencies. Just fetch() and a few lines of code to send transactional emails from your Node.js app.

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/4 min read

Postmark vs SMTPfast: Transactional Email Compared

Postmark built its reputation on delivery speed. SMTPfast built its on developer simplicity. Here is how they compare.

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/4 min read

Send Transactional Emails from Python with SMTPfast

Use the requests library to send emails from any Python app. Includes FastAPI and Django integration patterns.

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/4 min read

SendGrid vs SMTPfast: Which Email API Should You Choose?

An honest head-to-head comparison of SendGrid and SMTPfast. Where each wins, where each falls short, and who should pick what.

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/5 min read

Email Webhook Best Practices: Handle Bounces, Complaints, and Deliveries

Webhooks are how your app stays in sync with email delivery. Here is how to set them up correctly and handle every event type.

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/3 min read

How to Switch from Resend to SMTPfast in 5 Minutes

SMTPfast is API-compatible with Resend. Switch by changing two lines of code: your base URL and API key.

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/7 min read

Getting Started with SMTPfast

Sign up, verify a domain, mint an API key, and send your first email through SMTPfast in about ten minutes. Curl, Node, and Python examples included.

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/9 min read

Email Deliverability: Why Your Emails Land in Spam

The actual reasons mail lands in spam: weak DKIM/SPF/DMARC, dirty lists, complaint rate, content tells, and IP warmup. With concrete fixes for each.

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/2 min read

Transactional vs Marketing Emails: What is the Difference?

Understanding the difference between transactional and marketing emails, and why it matters for deliverability and compliance.

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/2 min read

Resend vs SendGrid vs SMTPfast: Which Email API to Use

An honest comparison of three email API providers. Pricing, features, developer experience, and who each one is best for.

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/9 min read

10 Reasons Your Emails Land in Spam (And How to Fix Each One)

A developer's checklist of the ten signals every spam filter scores you on, with concrete fixes and the specific DNS records, headers, and metrics that matter.

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/3 min read

Email API Best Practices for Production Apps

Lessons from sending millions of transactional emails. Error handling, retry logic, templates, and monitoring.

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/9 min read

Building Email Templates with React (No Framework Required)

Build readable, type-safe email templates with React Email. Covers setup, rendering, local preview, Tailwind, Outlook quirks, and plain text generation.

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/3 min read

AWS SES Setup: From Zero to Production in 30 Minutes

A step-by-step guide to setting up AWS SES for email sending. Domain verification, sending limits, and production access.

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