<blog>

Field notes on sending email.

Working code, honest trade-offs and the protocol details nobody explains properly.

latestguide·Apr 12, 2026

How to Send Transactional Emails with Node.js

Working code, honest trade-offs, and when each pattern fits: nodemailer over SMTP, provider SDKs, and a coordination layer on top.

Read the guide
guide·Apr 11, 2026

Best Transactional Email Services for Developers (2026)

SES, Postmark, Mailgun and Resend compared on pricing and deliverability.
guide·Apr 11, 2026

How to Send Transactional Emails with Gmail SMTP (Node.js & Python)

Set up Gmail or Google Workspace SMTP with App Passwords for transactional email.
<sendstreak-academy>

Email infrastructure, from EHLO to DMARC.

Short, standalone lessons on the protocols under your sends. Read them in order or jump to the one that just broke your deliverability.

11 lessons·free, no signup
start with lesson 01
  1. 01 What are transactional emails? trigger → send
  2. 02 SMTP basics EHLO
  3. 03 SMTP vs IMAP vs POP3 587 · 993 · 995
  4. 04 SMTP status codes 250 · 421 · 550
  5. 05 What is SMTP relay? relay
  6. 06 TLS and STARTTLS STARTTLS
  7. 07 Email headers Received:
  8. 08 What is SPF? v=spf1
  9. 09 What is DKIM? DKIM-Signature
  10. 10 What is DMARC? v=DMARC1
  11. 11 Setting up SPF, DKIM and DMARC p=reject

Done reading about retries? Let something else handle them.

Keep your backend, add templates, routing and logs. 100 emails a day free.

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