SMTP Connection Timeout on Port 25 / 465 / 587

Cloud and serverless runtimes (Vercel, AWS Lambda, Cloudflare Workers, GCP) block outbound TCP port 25/465 SMTP connections.

1. Immediate Code & SKU Fix

Replace With SKU: resend HTTP API (port 443)

Install Command: npm install resend

Required Env Vars: RESEND_API_KEY

import { Resend } from 'resend';
const resend = new Resend(process.env.RESEND_API_KEY);
await resend.emails.send({ from: 'onboarding@resend.dev', to, subject, html });

2. Verified Hot-Swap Fallback Route

JTBD: transactional-email

Primary: resend → Fallback: postmark

liveHealth: operational · autoActOk: true

Maximum deliverability paranoia — Postmark

GET /api/rescue JSON (<2 KB)Falsify Pick (/api/falsify)

Matched Error String Signatures (6)

smtp connection timeoutport 25econnrefused 25etimedout 465etimedout 587nodemailer

curl -s "https://getagentdepot.com/api/rescue?q=smtp%20connection%20timeout"

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