Migrate from Resend

Add your sending domain under Settings → Domains in Plunk. Plunk shows three CNAME records named <token>._domainkey, pointing to <token>.dkim.amazonses.com. Add them at your DNS provider and Plunk marks the domain verified once they resolve.

You do not need to remove anything first. Resend signs with a TXT record at resend._domainkey and puts its SPF and MX records on the send. subdomain. Plunk’s DKIM selectors are different, so both sets of records can live side by side and Resend keeps working while you move.

Plunk also offers an optional custom MAIL FROM domain: an MX and an SPF TXT record on a plunk. subdomain. It aligns bounces with your domain and is worth adding, but sending works without it.

Export contacts from the Contacts page in Resend with Export. Exports over 1,000 contacts arrive by email. Resend does not document the export’s columns, so open the file and check that every contact you have unsubscribed is marked as such.

If it is not, use the API instead: GET /contacts returns each contact’s email, first_name, last_name and unsubscribed. Note the flag is inverted: write subscribed as the opposite of unsubscribed.

Then download Resend’s suppression list (Suppressions → Download CSV). It holds addresses that bounced or complained. Add each one to your import with subscribed set to false.

email,firstname,lastname,subscribed
ana@acme.com,Ana,Ruiz,true
tom@northwind.io,Tom,Berg,false
old@contoso.com,,,false

Resend has no template export in the dashboard, but GET /templates/{id} returns each template’s html, subject and variables. Create a template in Plunk, switch the editor to HTML and paste it in.

Plunk renders variables with Liquid. Resend’s {{{PRODUCT}}} becomes {{PRODUCT}}. Its reserved keys map to contact fields: {{{FIRST_NAME}}} to whatever you named that CSV column, lowercased, such as {{firstname}}, {{{EMAIL}}} to {{email}} and {{{UNSUBSCRIBE_URL}}} to {{unsubscribeUrl}}.

await resend.emails.send({
  from: 'Acme <hello@acme.com>',
  to: 'ana@acme.com',
  subject: 'Welcome to Acme',
  html: '<p>Thanks for signing up.</p>',
  replyTo: 'support@acme.com',
});

const response = await fetch('https://send-api.akmarketingseo.com/v1/send', {
  method: 'POST',
  headers: {
    'Content-Type': 'application/json',
    Authorization: `Bearer ${process.env.PLUNK_SECRET_KEY}`,
  },
  body: JSON.stringify({
    from: {name: 'Acme', email: 'hello@acme.com'},
    to: 'ana@acme.com',
    subject: 'Welcome to Acme',
    body: '<p>Thanks for signing up.</p>',
    reply: 'support@acme.com',
  }),
});

if (!response.ok) {
  throw new Error(`Plunk returned ${response.status}`);
}

If your app sends through Resend’s SMTP server instead of the API, only the settings change:

# Before (Resend)
host:     smtp.resend.com
username: resend
password: your Resend API key

# After (Plunk)
host:     smtp.useplunk.com
port:     587 (STARTTLS) or 465 (TLS)
username: plunk
password: your Plunk secret key (sk_...)

Resend’s API returns each automation as JSON (GET /automations/{id}), which is a useful checklist, but there is no import: you rebuild each one as a Plunk workflow. Most steps have a direct counterpart:

• Send Email

  Send email step, using a Plunk template.

• Delay

  Delay step, in minutes, hours or days.

• Wait for Event

  Wait for event step.

• Condition

  Condition step, with as many branches as you need.

• Contact Update

  Update contact step.

• Add to Segment

  Set a contact field with an Update contact step, and build a dynamic segment on that field.

Events you send to Resend with POST /events/send go to Plunk’s POST /v1/track instead, with email, event and an optional data object. The track endpoint accepts your public key, so it can be called from the browser.

Plunk has no global webhook setting. Instead, you create a workflow that starts on an event and add a Webhook step that posts to your URL. One workflow per event you care about, each with its own URL and headers if you want them.

Plunk’s email.open and email.click fire on the first open and first click of each email, not on every one. The payloads differ, so the code that reads them needs updating. Plunk’s payload for each event is listed in the webhooks guide.

1. 1

   Send to yourself first

   Send a few real templates from Plunk to your own inboxes and check rendering, links and variables. Gmail’s “Show original” should report DKIM pass for your domain.
2. 2

   Move one kind of email at a time

   Switch one flow, such as password resets, and watch delivery in Plunk for a day before moving the rest. Resend stays available as a fallback the whole time.
3. 3

   Remove the old records last

   Once nothing sends through Resend any more, wait a few days for any retries to settle, then remove its DNS records and cancel the plan.