Postboi or Resend?

• Pick Postboi if you want email working in your app today, from one command, at a lower bill, with lists and forms included rather than priced separately.
• Pick Resend if you need an SDK in a language other than TypeScript, SMTP, a dedicated IP, or a provider with a longer track record. Postboi is newer, and still pre-release.

Postboi. Run npx postboi init. It sets up your account and token, and mail() sends straight away from send.postboi.email to any address, up to 100 a day until you verify a domain of your own. An agent can do the whole thing for you from one prompt and hand you a link to claim the project.

Resend. Sign up, make an API key and install the SDK. Until you verify a domain, Resend only sends from its testing address to the address you signed up with, so reaching a real user means adding DNS records first.

The same receipt, sent from each SDK.

import { Resend } from 'resend'

const resend = new Resend(process.env.RESEND_API_KEY)

const { error } = await resend.emails.send({
	from: 'Acme <hello@acme.com>',
	to: 'ada@example.com',
	subject: 'Your receipt',
	html: '<p>Thanks for your order.</p>',
})
if (error) throw new Error(error.message)

import { mail } from 'postboi'

// No from needed: it sends from your send.postboi.email address.
await mail({
	to: 'ada@example.com',
	subject: 'Your receipt',
	body: '<p>Thanks for your order.</p>',
})

Resend's SDK hands back { data, error } and leaves checking it to you. mail() throws a PostboiError when a send fails, so a failure can't go unnoticed. Both take attachments, headers, tags, scheduling and idempotency keys, and Resend documents its fields.

The cheapest plan on each side for a month of email. Postboi prices in pounds and Resend in dollars, so Postboi's figure is also shown in dollars at $1.32 to the pound. Resend's prices are from its pricing page on 25 September 2026.

The same sums at round numbers:

At 50,000 emails Postboi is £13 and Resend is $20. Both free tiers are 3,000 a month at 100 a day. Every Postboi plan meters past its volume rather than stopping, and the full rate card is on the pricing page.

Not counted on either side: tax, a dedicated IP ($30 a month on Resend's Scale, which Postboi doesn't sell), and Resend's marketing plan for broadcasts, below.

Lists cost nothing extra on Postboi. Resend's broadcasts are a separate marketing plan charged by contact, $40 a month for 5,000. On Postboi a broadcast is just email on your plan, and there is never a per-contact charge.

Moving from Resend to Postboi's own sending costs you these. Where it's about Resend, the link goes to Resend's own page.

• Other languages. Resend has official SDKs for Node.js, Python, Ruby, PHP, Go, Rust, Java and .NET. Postboi's SDK is TypeScript; anything else talks to the REST API.
• SMTP. Resend takes mail over SMTP, which suits software you can't change, like a CMS or a self-hosted app. Postboi has no SMTP relay for sending into it.
• Dedicated IPs. Resend sells one on Scale, from $30 a month (pricing). Postboi sends every account under its own isolated identity on shared IPs.
• Hosted templates and React in the call. Resend can send a template stored in Resend, or a React element passed straight to send(). On Postboi you render to HTML first; React Email's render() does it in one line.
• Billing in dollars. Postboi prices and bills in pounds, so a team paying in dollars pays at the exchange rate.
• Track record. Resend has been sending at scale for longer. Postboi is pre-release. Its mail goes out through Amazon SES in the EU, and the delivery record publishes how fast it arrives, how often we were up and every incident, from our own figures.

The postboi SDK can send through Resend as well as through Postboi, alongside 40 other providers. If you already have a Resend account, adopt the SDK now, keep sending through Resend, and move to Postboi's own sending later by changing configuration rather than code:

// postboi.config.ts: the same mail() calls, sent by your Resend account
import { config } from 'postboi'

export default config({
	provider: 'resend', // and 'postboi' the day you move
	default: { from: 'Acme <hello@acme.com>' },
})

Moving from Resend goes through it step by step: every field of resend.emails.send() mapped, webhooks, domains, and what stays behind. The docs compare the SDKs in more detail.

Is Postboi a wrapper around Resend or another provider?

No. Postboi is an email provider in its own right: one token is a complete setup, with its own sending, receiving, domains and delivery tracking. Sending through another provider is an option, not a requirement.

Is Postboi built for transactional email?

Yes, it's the main thing it's for. Sign-in links, codes, receipts and resets get delivery status, idempotency keys, retries, suppressions and webhooks, and sending pauses itself if bounces or complaints climb. The other channels are extras on top.

What is Tempboi?

Postboi's throwaway inboxes, at tempboi.email. A test or an AI agent makes an address with no account, signs up for something with it, and reads the code or link back out. Email for agents shows the whole loop.

Which is cheaper for 50,000 emails a month?

Postboi: £13 on Starter, about $17.16, against $20 on Resend's Pro.

Do I need to set up DNS to try it?

Not on Postboi. On Resend, you need a verified domain to send to anyone but yourself.

Can I move from Resend without rewriting my sends?

Yes. Point the postboi SDK at your Resend account first, then switch the provider when you're ready. Your mail() calls stay the same. Moving from Resend maps every field.

What would I give up by moving from Resend?

SDKs in languages other than TypeScript, an SMTP relay, dedicated IPs and Resend-hosted templates. Postboi's own sending is also newer. If you need any of those, keep Resend as the provider and use Postboi's SDK on top.