Can you add an email API without changing Google Workspace MX?

You can generally add an email-sending API while keeping Google Workspace MX records for incoming mail. MX controls where the domain receives messages; SPF, DKIM and DMARC support sending authentication and policy. For Emailer API, use the account’s returned DNS records and reconcile existing policies instead of replacing your Workspace configuration.

Separate incoming mail from outbound authentication

An instruction to verify a sending domain is not automatically an instruction to change its MX records. Keep the existing receiving service in place unless you intentionally plan a mail-routing migration. Start by recording the current DNS configuration so you can understand each proposed change.

Record	Role in this setup
MX	Routes incoming mail for the domain.
SPF TXT	Identifies servers authorized to send for the relevant domain.
DKIM TXT	Publishes a signing key at a provider’s selector.
DMARC TXT	Expresses policy and reporting preferences for authenticated mail.

Reconcile SPF instead of adding a second policy

Google’s guidance calls for one SPF record for a domain. If Google Workspace and another service both send using the same SPF domain, reconcile the authorized senders within the existing policy. Do not publish two separate v=spf1 records at the same name or overwrite the policy with a value copied from an unrelated account.

Example: a domain already authorizes Workspace and needs an additional legitimate sender. Compare the existing policy with the exact record Emailer API returns, retain required existing senders and review the resulting policy, including SPF lookup constraints. Use the provider documentation if the policy is already complex.

Keep DKIM selectors and DMARC policy deliberate

Different providers can use distinct DKIM selectors. Add the requested selector and value while preserving the keys another active sender still uses. Do not assume that a record named for one selector can replace another service’s key.

Review the domain’s existing DMARC policy rather than adding a conflicting duplicate. Authentication and alignment depend on the actual sending configuration. A DNS record passing verification does not guarantee that every message will reach an inbox.

Choose the sending domain with the callback in mind

A sending subdomain can separate some DNS configuration, but choose it alongside the application’s hosting requirements. Emailer API account, security and appointment verification requires an HTTPS callback on the exact verified sending domain. Verifying mail.example.com does not make a callback hosted only at app.example.com equivalent.

Plan how that endpoint will be hosted before committing to the domain. Financial receipts and paid orders use the supported Stripe verification path. Follow the current API contract for the message type instead of choosing a subdomain solely because it looks tidy.

Apply the returned setup stages and check again

Emailer API checks ownership and SPF before DKIM provisioning. Once the signing record is available, publish the returned DKIM and DMARC values and recheck. This staged flow means you may not receive every record at the first step.

The included helper can inspect DNS and prepare supported TXT additions through an authorized Cloudflare connection. Review the plan on the site before applying it. Existing records are not silently overwritten; plans expire and are rechecked. If your DNS is elsewhere, use the same returned records in that provider’s supported editor.

After the records pass, complete the event and template integration and validate a real intended payload. Working Google Workspace inboxes and a verified sending domain are useful checks, but neither alone proves the new application email workflow is complete.

Common questions

Do I need a separate Google Workspace mailbox for every sender?

Receiving-mail configuration and API sending authorization are separate. Follow the sending-domain and owner checks in Emailer API rather than inferring readiness from a Workspace mailbox.

Can I copy another customer’s SPF or DKIM values?

No. Use the records returned for your account and domain, then reconcile them with your existing DNS policies.

Continue with a related guide

Sources and next steps

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Reviewed by the Emailer API editorial assistant against the linked documentation. This guide explains the documented workflow; it is not a report of a new integration test.