Set Up Sender Domain

You can start sending on Synapse's shared domain right away — no setup required. A sender domain tells email providers (Gmail, Outlook, etc.) which addresses Synapse is authorized to send from. Verifying your own domain is an optional upgrade that improves deliverability and puts your brand on every email.

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Two Options

Shared Domain

On every plan, including Free, you can send from Synapse's shared domain with no setup. Your emails go out from an address like [email protected]. This works immediately in both test and live mode — you can go live and send real email on the shared domain without verifying a domain of your own.

Custom Domain

On any plan, you can also verify your own domain (e.g., [email protected]) as an optional upgrade. Sending from your own domain gives you isolated sender reputation and puts your brand in the "From" address. It is recommended for production, but not required — you can go live on the shared domain first and add a custom domain later without any code changes.

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Setting Up a Custom Domain

Step 1: Add Your Domain

1. Go to Settings in the dashboard sidebar.
2. Click Sender Domains.
3. Click Add Domain.
4. Enter your domain name (e.g., yourcompany.com).
5. Click Continue.

After you add a domain, Synapse automatically detects your DNS provider and shows it with a branded icon. This helps you identify where to add records and links directly to your provider's DNS management panel.

Step 2: Configure DNS Records

There are two ways to add the required DNS records, depending on your DNS provider.

Recommended: Auto-Configure with Cloudflare

If your domain uses Cloudflare nameservers, Synapse detects this automatically and offers one-click DNS configuration via Domain Connect. This is the fastest and most reliable path -- no manual record entry, no typos, no waiting for propagation.

1. On the domain detail page, click the Auto configure button (shown with the Cloudflare icon).
2. You are redirected to Cloudflare's authorization page.
3. Click Authorize to allow Synapse to add the required DNS records to your Cloudflare zone.
4. You are redirected back to Synapse. The records are configured and verified automatically.

Manual Setup (All Other Providers)

For domains not on Cloudflare, Synapse detects your DNS provider and links directly to their DNS management panel. Synapse recognizes 15 providers including Namecheap, GoDaddy, AWS Route 53, Google Cloud DNS, DigitalOcean, Vercel, and more. See the full provider list for details.

Add these records in your provider's DNS settings:

Step 3: Verify

If you used Cloudflare auto-configure, verification happens automatically after the redirect. You can skip this step.

For manual DNS setup, verification starts automatically after records are configured. You can also trigger a manual check:

1. Go back to the Sender Domains page in Synapse.
2. Click Verify next to your domain.

For Cloudflare auto-configure, verification typically completes within seconds. For manual setups, propagation may take a few minutes to a few hours depending on your provider.

Step 4: Check Status

Your domain will show one of these statuses:

Once verified, your custom domain is available for use in your email templates and flows. Until then, sends continue to go out on the shared pyrx.tech domain, so you're never blocked from sending while a custom domain is pending.

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Using Your Sender Domain

After verification, set up your sending identity:

1. Go to Settings > Workspace.
2. Under Default Sender, set your default "From" name and email address using your verified domain.
3. When creating templates, you can override the sender per template if needed.

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Re-Verifying Your Domain

If you made changes to your DNS records after the initial setup (for example, to fix an incorrect value), you can trigger a re-verification:

1. Go to Settings > Sender Domains.
2. Click on the domain you want to re-verify.
3. Click the Verify button.
4. Synapse will re-check all DNS records and update the status for each one individually.

The domain detail page shows per-record verification status, so you can see exactly which records are passing and which need attention.

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Troubleshooting

Verification keeps failing

• Double-check that all DNS records match exactly what Synapse shows.
• Make sure you haven't accidentally added extra spaces or characters.
• Some DNS providers add your domain automatically to CNAME targets -- check if the record looks like s1._domainkey.yourcompany.com.yourcompany.com (doubled) and correct it.
• Wait at least 1 hour before retrying, as DNS propagation takes time.

Auto-configure button not showing

The auto-configure button only appears for domains hosted on Cloudflare. If your domain uses a different DNS provider, add the DNS records manually using the values shown in the dashboard.

Emails going to spam

• Make sure your DKIM record is verified.
• Check that your SPF record is in place.
• If you just set up the domain, allow a few days for email providers to build trust with your new sending identity.

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Looking for More?

• Sender Domain Setup (Full Reference) -- DNS records explained, all supported providers, advanced troubleshooting
• Domains API Reference -- manage sender domains programmatically