Chapter 11: The Deliverability Checklist

In Klaviyo, confirm that the branded sending domain is verified and activated, rather than simply added to the account. Use the records generated for your own account and coordinate changes with whoever manages DNS.

What to check: Check the domain’s current status and review Klaviyo’s setup instructions.

Inspect the authentication results of an actual message sent through your platform. SPF identifies authorized sending infrastructure; DKIM adds a verifiable signature. DMARC checks alignment with the visible From domain and defines how failures should be handled.

What to check: Have your platform or technical owner verify SPF, DKIM, and DMARC results, including alignment.

A DNS record existing is not the same as a real message passing. Review all legitimate services sending for the domain before tightening DMARC enforcement.

Mailbox providers set their own requirements, including additional rules for bulk senders. Use the current official guidance instead of assuming every provider uses the same thresholds.

What to check: Confirm authentication, unsubscribe, and sending requirements with your platform or technical owner.

Review the signup sources feeding your list. A subscriber should understand which brand will contact them and what they are signing up for. Avoid purchased, rented, or scraped lists.

What to check: Spot-check recent profiles and the forms, imports, or integrations that created them. Review questionable sources before sending to those contacts.

Review how your platform handles unsubscribes, spam complaints, and hard bounces. Confirm imports and integrations do not accidentally restore marketing eligibility.

What to check: Check exclusions on both campaigns and flows. Preserve suppression history when moving data between systems.

Use a simple approach to recent engagement and customer activity. Apple Mail Privacy Protection can create open events without a person reading the email, so opens alone are not reliable proof of interest.

What to check: Review privacy-affected opens alongside meaningful clicks, purchases, signup recency, and your normal buying cycle. Customer activity does not override an unsubscribe.

You do not need dozens of segments. You need a clear reason for including or excluding someone.

Decide how you reduce or stop routine marketing to people who consistently show no meaningful activity. The appropriate window depends on sending frequency, purchase cycle, and available signals.

What to check: Document your inactivity rule and review any re-engagement approach before including a large dormant audience.

Send a test and follow the unsubscribe path. Make sure people can stop marketing without signing in or navigating a confusing process.

What to check: Verify the request changes the recipient’s marketing eligibility as intended. Preferences should not obscure the ability to unsubscribe.

A footer link and a provider-supported one-click unsubscribe header are different things. Confirm your platform supports the required mechanism for marketing messages and processes requests promptly.

What to check: Verify this with your platform rather than assuming a footer link covers it. Yahoo requires bulk senders to honor unsubscribes within two days.

A new domain, a platform migration, or a sudden expansion into an inactive audience needs a deliberate sending plan.

What to check: Follow the platform’s guidance for your particular setup. Avoid blindly applying a generic warm-up schedule. Watch results as volume changes.

Look at the experience of an individual subscriber. Campaigns and automated messages can overlap even when each looks reasonable on its own.

What to check: Review frequency controls, flow timing, and exclusions. Decide which messages should take priority instead of assuming one account-wide setting solves every overlap.

Use a recognizable sender name and a subject line that accurately reflects the message. Make the brand, purpose, and destination links understandable.

What to check: Test the message, review links and rendering, and check that important information remains readable when images do not load.

Clear content supports the recipient experience. It does not compensate for poor audience quality or authentication problems.

Look for changes after a campaign, audience expansion, or new signup source. Compare like-for-like data: providers and platforms may calculate rates differently.

What to check: Investigate spikes and identify the affected audience or source before repeating the send.

A failed address, a temporary deferral, and a provider block need different responses.

What to check: Read the platform’s delivery reasons. Identify whether failures cluster around a provider, audience source, or recent configuration change. Share representative error codes with platform support.

Deliverability needs a named owner and a repeatable review habit.

What to check: Assign responsibility for reviewing trends, investigating issues, and recording changes. Review more closely during migrations, major volume changes, or active problems.

Suggested operating habit: A weekly review is a practical starting point. Adjust it to your sending activity and current issues.

Confirm the number is active and any required verification or registration is complete.

An email subscription is not automatically an SMS subscription. Verify the SMS consent status and collection method.

Test the opt-out process and review applicable regional sending rules and platform settings for the markets you serve.

Review failure reasons and recurring errors with your platform rather than repeatedly retrying the same failed recipients.