Deliverability Audit & Optimisation

If your emails are not reaching the inbox, nothing else in your programme matters.

Deliverability is the foundation of every email programme. An open rate, a click rate, a revenue figure — all of these numbers only reflect the subscribers your emails actually reached. If a significant proportion of your sends are landing in the spam folder, or being silently filtered before they arrive at all, your programme's real performance is substantially worse than your Klaviyo dashboard suggests. And the longer a deliverability problem is left unaddressed, the harder it becomes to recover from.

The FlowFixer Deliverability Audit and Optimisation project identifies exactly where your emails are landing, diagnoses the root causes of any inbox placement problems, and implements the technical and strategic changes needed to restore and maintain strong deliverability — across every major inbox provider, including Gmail, Outlook, Apple Mail, and the mobile clients used by a growing proportion of your subscriber base.

What the engagement covers

Inbox placement testing

We run structured inbox placement tests across the major email clients and inbox providers — measuring not just whether your emails are delivered, but whether they are landing in the inbox, the promotions tab, or the spam folder. For brands sending to international audiences, we test across the regional providers that matter for their specific subscriber base. This gives us a precise, evidence-based picture of your current deliverability situation rather than the partial view that Klaviyo's own metrics provide.

Sending domain and authentication audit

We audit your full sending domain configuration — SPF, DKIM and DMARC records, custom tracking domain setup, and the alignment between your sending infrastructure and Klaviyo's requirements. Authentication failures and misconfigurations at this level are one of the most common causes of deliverability problems in Klaviyo accounts, and they are frequently invisible to the brands experiencing them because Klaviyo's own reporting does not surface them clearly.

Sender reputation assessment

An assessment of your sending domain and IP reputation across the major reputation monitoring services — including Google Postmaster Tools data, Microsoft SNDS signals, and blocklist status across the key RBLs. If your domain or sending IP has accumulated reputation damage, we identify the extent of it and map out the recovery path.

List health and engagement analysis

Deliverability problems are almost always partly a list health problem. We analyse your subscriber engagement distribution, your unengaged cohort percentage, your bounce and complaint rates, and your current suppression management practices — and identify the specific list hygiene actions that will have the most immediate positive impact on your inbox placement rates.

Content and sending practice review

Inbox providers assess content signals as well as sender reputation. We review your campaign and flow content for the patterns — structural, linguistic and technical — that trigger spam filters or reduce engagement weighting. We also assess your sending frequency, send time distribution, and warm-up practices for any new domains or sending volumes.

Optimisation implementation

The audit findings are not presented as a report for your team to implement independently. We implement the technical fixes — authentication corrections, domain configuration, Klaviyo account settings — and work with you on the list hygiene and strategic changes that require internal action. For brands with active deliverability crises, we triage and implement the highest-impact fixes first to begin recovery as quickly as possible.

Monitoring and verification

After implementation, we monitor inbox placement rates and sender reputation metrics through the recovery period — verifying that the changes are having the expected effect and making adjustments where needed. Deliverability recovery is not instantaneous, and the monitoring phase ensures that the programme is on the right trajectory before we hand back full ownership.

Klaviyo-specific deliverability considerations

Deliverability management in Klaviyo has platform-specific nuances that generic deliverability advice does not account for. Klaviyo's shared IP infrastructure, its default attribution and engagement tracking settings, its handling of consent data, and the interaction between its sending architecture and Gmail's current filtering models all require expertise that comes from working inside Klaviyo accounts daily — not from applying general email deliverability principles to a platform they were not designed for.

Our specialists understand how Klaviyo's infrastructure works, what its defaults do and do not do well for deliverability, and where the platform-specific configuration changes make the most difference to inbox placement. That specificity is the difference between a deliverability intervention that works and one that addresses the symptoms without finding the cause.

Frequently asked questions

Our open rates have dropped significantly. How quickly can you identify the cause?

In most cases, the primary cause of a significant open rate decline is identifiable within the first two to three days of the audit — once we have inbox placement test data, authentication audit results and Google Postmaster Tools access in hand. Implementation of the highest-impact fixes typically begins within the first week. Full recovery of sender reputation takes longer and depends on the severity of the underlying problem, but visible improvement in inbox placement is usually measurable within two to four weeks of the initial fixes going in.

Do we need to pause our sending during the audit?

In most cases, no. We conduct the audit and implement fixes while your programme continues sending. The exception is for brands with severe reputation damage where continued sending is actively making the situation worse — in those cases, we will recommend a structured pause and warm-up sequence as part of the recovery plan.

Can deliverability problems be prevented rather than fixed reactively?

Yes — and prevention is significantly less disruptive and costly than recovery. If your programme is currently delivering well, a deliverability audit is a valuable proactive investment that identifies the leading indicators of future problems before they become crises. We provide clear guidance on the ongoing monitoring practices and list hygiene disciplines that keep inbox placement rates high over the long term.