Domains and DNS

Authenticate every domain used in the visible From address. Alignment between the sending account, From domain, and authentication policy is central to trustworthy delivery.

Add a domain

1. Open Domains & DNS.
2. Choose Add domain.
3. Enter the organizational domain or sending subdomain you control.
4. Save it and open the domain detail.
5. Copy the records shown for your configuration.

A dedicated sending subdomain can separate mail operations from other domain uses, but it still needs an intentional reputation and policy plan.

Publish authentication

• SPF authorizes the sending infrastructure. Maintain one valid SPF policy for a hostname and include only approved sources.
• DKIM signs messages. Generate or import a key, note its selector, and publish the exact TXT value.
• DMARC tells receivers how to evaluate aligned SPF or DKIM and where to send reports. Begin with a policy suited to your rollout and tighten it based on observed reports.

DNS providers differ in how they display the host field. Avoid duplicating the zone name when the provider appends it automatically.

DKIM keys

RSender can generate a key, import key material, enable or disable it, and generate the TXT record for publication. Protect private key material; only the public TXT value belongs in DNS.

Use a unique, documented selector and rotate keys according to your security policy. Confirm that the enabled key matches the published selector before a campaign.

Verify

1. Publish all records at the DNS provider.
2. Wait for DNS propagation.
3. Recheck the domain in RSender.
4. Inspect SPF, DKIM, and DMARC individually.
5. Send a test to an inbox you control and inspect authentication results.

Do not treat a pending record as a reason to start production traffic. TTL, delegation, formatting, and cached answers can delay or invalidate a change.

Troubleshooting

• Confirm the record is published under the correct zone.
• Remove copied quotation marks if the provider adds them automatically.
• Check for multiple SPF records.
• Confirm the DKIM selector in RSender matches DNS.
• Query from more than one resolver if propagation appears inconsistent.
• Use domain detail and recheck before changing unrelated settings.

Next: connect a sending account.