Deliverability·API·Sender reputation
Practical guides for sending reliable transactional email.
Ten free SMTP services compared for apps, CMSs and devices: free-tier limits, daily caps, ports and TLS. Every number checked on the provider's own pages.
SMTPfast, Mailtrap, Postmark, Twilio SendGrid and Amazon SES compared for SaaS products: free tiers, real prices, inbound email, and the tradeoffs each one makes.
Every action in the SMTPfast dashboard now has an API endpoint, the hosted MCP server covers almost all of it, and a new command-line tool turns each endpoint into a command. Tests keep all four in step.
SMTPfast now stores your email templates. Write one with variables, preview it on desktop, mobile and dark mode, publish it, and send it by id or alias. The API matches Resend's Templates API.
Turn [email protected] into a real inbox inside SMTPfast. Received mail and your replies group into threads, and AI agents can write drafts that a person reviews and sends. The API matches Resend's Inboxes API.
DigitalOcean blocks outbound SMTP ports 25, 465 and 587 on Droplets and advises against running your own mail server. Here is how to tell if the block is what broke your emails, and two ways around it: an HTTPS API on port 443, or SMTP on port 2525.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
Broadcasts let you send product updates and newsletters to subscribed contacts with drafts, tests, scheduling, suppression checks, and delivery metrics.
Nine transactional email APIs ranked by what matters: developer experience, pricing, deliverability, and where each one breaks. Code samples for every one.
Watch every send, delivery, bounce, open, and click stream into your dashboard in real time. tail -f for email.
Drop a form on your site, collect contacts straight into SMTPfast, with double opt-in and webhook events out of the box.
A leaked API key can send thousands of emails on your behalf in minutes. Here is how to keep your keys safe.
Three DNS records stand between your emails and the spam folder. Here is what each one does and exactly how to set them up.
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.
Mailgun has been a developer favorite for years. SMTPfast is the new challenger. Here is how they stack up on DX, pricing, and features.
A step-by-step guide to moving your transactional email from SendGrid to SMTPfast. Includes code before and after for every language.
No SDK, no dependencies. Just fetch() and a few lines of code to send transactional emails from your Node.js app.
Postmark built its reputation on delivery speed. SMTPfast built its on developer simplicity. Here is how they compare.
Use the requests library to send emails from any Python app. Includes FastAPI and Django integration patterns.
An honest head-to-head comparison of SendGrid and SMTPfast. Where each wins, where each falls short, and who should pick what.
Webhooks are how your app stays in sync with email delivery. Here is how to set them up correctly and handle every event type.
SMTPfast is API-compatible with Resend. Switch by changing two lines of code: your base URL and API key.
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.
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.
Understanding the difference between transactional and marketing emails, and why it matters for deliverability and compliance.
An honest comparison of three email API providers. Pricing, features, developer experience, and who each one is best for.
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.
Lessons from sending millions of transactional emails. Error handling, retry logic, templates, and monitoring.
Build readable, type-safe email templates with React Email. Covers setup, rendering, local preview, Tailwind, Outlook quirks, and plain text generation.
A step-by-step guide to setting up AWS SES for email sending. Domain verification, sending limits, and production access.