Resend Setup Guide

Connect Resend to send up to 100 notification emails per day (3,000/month) for free.

Free tier details

Step 1: Create a Resend account

1. Go to resend.com/signup
2. Sign up with your email address or GitHub account
3. Confirm your email if prompted

Step 2: Verify your domain

This step is critical. Without a verified domain, Resend only lets you send emails to your own email address (the one you signed up with). To send to anyone else, you must verify a custom domain.

1. In the Resend dashboard, go to Domains in the left sidebar
2. Click Add Domain
3. Enter your domain name (e.g., yourdomain.com)
4. Resend will show you DNS records to add. You need to add two types of records at your domain registrar or DNS provider:

SPF record

DKIM record

After adding the DNS records:

1. Go back to the Resend dashboard
2. Click Verify on your domain
3. DNS propagation can take anywhere from a few minutes to 48 hours, though it usually completes within 5–30 minutes
4. Resend will show a green checkmark once the domain is verified

Step 3: Create an API key

1. In the Resend dashboard, click API Keys in the left sidebar
2. Click Create API Key
3. Name it something like "FormBlade"
4. For permissions, select Sending access (full access is not needed)
5. Optionally restrict the key to your verified domain for extra security
6. Click Create
7. Copy the API key immediately — it starts with re_ and is only shown once

Step 4: Configure FormBlade

1. Log in to your FormBlade dashboard
2. Open the form you want to configure
3. Go to the Settings tab
4. Under Email Provider, select Resend
5. Paste your API key (starting with re_) into the API Key field
6. Set your From Email to an address on your verified domain (e.g., forms@yourdomain.com)
7. Optionally set a From Name
8. Click Save

Step 5: Send a test email

1. Click Send Test Email in the Email Provider section
2. Check your inbox for the test notification
3. If it fails, verify that your domain is verified and the "From Email" uses that domain

Troubleshooting

"Validation error" or "From address not allowed"

• The "From Email" in FormBlade must use your verified domain. For example, if you verified yourdomain.com, you can use forms@yourdomain.com, hello@yourdomain.com, etc.
• You cannot use a Gmail, Yahoo, or other free email address as the "From Email" with Resend

"API key is invalid" error

• Make sure you copied the full API key (starts with re_)
• Check for extra spaces before or after the key
• If the key was restricted to a specific domain, make sure your "From Email" uses that domain

Domain verification stuck

• DNS propagation can take up to 48 hours in rare cases
• Double-check the DNS records at your registrar match exactly what Resend shows
• Use a tool like MXToolbox to verify your DNS records are published
• Some registrars require you to omit the root domain from the record name (e.g., use resend._domainkey instead of resend._domainkey.yourdomain.com)

Can only send to myself

• This means your domain is not verified. Resend restricts unverified accounts to sending only to the account owner's email
• Complete the domain verification in Step 2 above
• If you do not have a custom domain, use Brevo instead

Resend free plan limitations

• 100 emails/day, 3,000/month — whichever limit you hit first
• 1 custom domain — you can only verify one domain on the free plan
• Domain verification required — without it, you can only send test emails to yourself
• No dedicated IP — shared sending reputation
• Basic analytics — open and click tracking available

The 100/day limit is sufficient for most forms. A typical contact form receives 5–20 submissions per day, well within the free tier.

Common gotchas

• Domain verification is mandatory for real use — Without a verified domain, Resend only allows you to send test emails to the email address you signed up with. All other recipients will be rejected. This is the single most common source of confusion.
• You need a custom domain you control — Resend does not support sending from free email addresses (Gmail, Yahoo, etc.). You must own a domain and be able to add DNS records. If you do not have a custom domain, use Brevo instead.
• DNS record format varies by registrar — Some domain registrars require you to enter just the subdomain portion of the record name (e.g., resend._domainkey), while others want the full name including the root domain (e.g., resend._domainkey.yourdomain.com). Check your registrar's documentation if verification fails.
• API key shown only once — The full API key (starting with re_) is only displayed when you create it. If you lose it, you must delete it and generate a new one.
• Domain-restricted API keys for extra security — When creating an API key, you can optionally restrict it to a specific verified domain. This means the key can only send from that domain, reducing the blast radius if the key is ever compromised.
• 1 domain on the free plan — The free tier allows only one verified domain. If you need to send from multiple domains, you will need a paid plan (starting at $20/month).
• Daily vs. monthly limits — The free plan has both a 100/day and 3,000/month limit. You are capped by whichever one you hit first.

Quick reference: where to find things in Resend