The Resend playbook

Resend sends the email. Your domain still has to earn the inbox.

Resend’s own guidance is to warm up gradually whenever you start on a new domain, and on the shared pool every sender starts on, the domain is the reputation that is yours. Keep sending through Resend exactly as you do now. Add your brand domain here and we build its reputation alongside Resend.

Start warming my domainSee Inbox Boost
The Resend playbook

Keep sending from Resend. Warm the domain here.

Step 1

Verify your domain in Resend

Until you do, the onboarding@resend.dev sender only delivers to the address on your Resend account. Resend asks for a DKIM TXT record at resend._domainkey and return-path records on a subdomain, send by default, and that label cannot be changed once the domain is created. Resend recommends sending from purpose-specific subdomains, one for newsletters and one for password resets, to keep reputation separate.

Step 2

Follow Resend’s guidance for a new domain

Resend’s warm-up guide says to warm up whenever you start on a new domain, IP or vendor, growing volume gradually and keeping bounce and spam rates low. Managed Dedicated IP Pools are warmed by Resend automatically, but every sender starts on the shared pool, where the domain is the reputation that is yours.

Step 3

Add your brand domain to Inbox Boost

Use the domain in your From address, such as yourapp.com. The return-path subdomain Resend sets up, send by default, stays with Resend. Inbox Boost builds the domain’s sender reputation alongside Resend. Nothing to connect: no Resend API key, no webhook, no change to your account.

Step 4

Keep sending with Resend

Your code keeps calling Resend exactly as it does now: password resets, receipts, product updates. Mailbox providers score the domain in your From address, so the reputation built here counts for every Resend send from yourapp.com.

Step 5

Check where Resend mail lands

Inbox placement tests show whether your mail reaches the inbox or Spam across the major mailbox providers, and blacklist monitoring keeps watching the domain afterwards.

  • Nothing to connect: no Resend API key, webhook or integration
  • Nothing to change: your code, templates and subdomains stay exactly as they are
  • Shared or dedicated pool: it works either way, because the reputation belongs to the domain
  • Watched afterwards: blacklist and authentication monitoring on your brand domain
Features Resend senders lean on

The parts of the platform this plan leans on.

Feature

Inbox Boost

Add a domain. We provision the sending server and publish your DNS.

Learn more Feature

Guided DNS setup

We write SPF, DKIM and return-path into your zone, not you.

Learn more Feature

Inbox placement testing

See whether you land in Primary, Promotions or Spam across providers.

Learn more
See it play out

A Resend domain, warmed without pausing a single send.

Four checkpoints, in order. Click any step or let it play.

resend · updates.yourapp.com
DKIM (resend)verified
return pathverified
sending historynone yet
Questions

Resend questions, answered.

Does Inbox Boost connect to my Resend account?
No. There is no API key, webhook or integration to set up. Inbox Boost works on your brand domain, and Resend keeps sending your mail exactly as it does now.
Resend says to ramp a new domain gradually. Does Inbox Boost replace that?
No, it works alongside it. Keep following Resend’s guidance: grow volume gradually and keep bounce and spam rates low. Inbox Boost builds the domain’s reputation alongside the mail Resend sends, and nothing in your Resend setup changes.
Resend warms dedicated IP pools. Is the domain covered by that?
Resend’s Managed Dedicated IP Pools are warmed automatically, and that covers the IPs. Resend’s own warm-up guide treats a new domain as something to warm up in its own right, and senders on the shared pool have no IPs of their own at all, so the domain is the reputation that is yours.
Which domain should I add?
Your brand domain, the one in your From address, such as yourapp.com. If you follow Resend’s advice and use separate subdomains for different kinds of mail, those stay set up in Resend exactly as they are, along with the return-path subdomain Resend creates.
Can I see whether it is working?
Yes. Inbox placement tests show where your Resend mail lands, inbox or Spam, across the major mailbox providers, and blacklist monitoring keeps watching the domain afterwards.
About the Resend facts on this page

Checked against Resend's own documentation on 12 October 2026. Resend is a trademark of its owner; SenderSignal is not affiliated with it.

Other transactional & smtp: Amazon SES, Mailgun, Postmark, SparkPost, Mailjet. All use cases.

Resend keeps sending

Build the reputation behind your Resend domain.

Start free, add your brand domain, and keep every API call going to Resend while its reputation builds.

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