Webclat / Klaviyo Practice
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Klaviyo deliverability diagnostics: the infrastructure behind inbox placement

When open rates drop or mail starts landing in spam, the instinct is to rewrite subject lines. Usually the actual cause is upstream: authentication misconfiguration, a reputation problem from sending to disengaged addresses, or a list-hygiene issue that's been compounding for months. We diagnose the infrastructure; content and send-cadence changes stay with your marketing team.

The infrastructure layer, in order of likelihood

CauseWhat it looks like
Authentication (SPF/DKIM/DMARC)Missing, misconfigured, or expired DNS records for your sending domain - inbox providers can't verify the mail is legitimately yours
Sending domain reputationA shared or newly warmed domain with a history of complaints, spam-trap hits, or bounce spikes
List hygieneSending to long-unengaged, hard-bounced, or purchased/imported addresses that trigger spam-filter heuristics
Suppression-list gapsPreviously-unsubscribed or complained addresses re-entering the send pool through a data-sync error (see our segmentation guide)
Sudden volume changesA large, unwarmed send spike (e.g. a list import or a Black Friday blast without a warm-up plan)

What a deliverability diagnostic covers

  • DNS record verification for SPF, DKIM, and DMARC alignment against your actual sending domain
  • Suppression-list reconciliation against unsubscribe, complaint, and hard-bounce history
  • Engagement-based list segmentation review - are you still mailing addresses that haven't opened in a year?
  • Sending-domain and IP reputation signals available through postmaster tools and Klaviyo's own deliverability reporting

The deliverable is a prioritized fix list with the DNS/config changes specified exactly. Implementing send-cadence or content changes based on the findings is a marketing decision.

Common questions

Is a deliverability drop usually about content or infrastructure?

Infrastructure, far more often than content. Authentication misconfiguration, sending to stale/unengaged lists, and shared-domain reputation problems account for the majority of the drops we're asked to diagnose - subject-line and content issues are a smaller, later-stage lever.

Do you fix email content or subject lines?

No. We diagnose and fix sending infrastructure - authentication, domain reputation signals, list hygiene. Content and subject-line testing belongs with your creative team or agency.

What is SPF/DKIM/DMARC and why does it matter for Klaviyo?

These are DNS-based email authentication standards that prove a message claiming to be from your domain was actually authorized to send. Inbox providers weight authentication heavily; a misconfigured or missing record is one of the most common causes of inbox placement drops.

How quickly can a deliverability problem be fixed?

Authentication fixes can propagate within hours to days depending on DNS TTLs. Reputation recovery from suppressing bad list segments and reducing volume to engaged recipients typically takes longer - measured in weeks, not days - since inbox providers rebuild trust gradually.

Find out why deliverability actually dropped.

Authentication, reputation, and list-hygiene diagnostics with a prioritized fix list.

Diagnose My Deliverability