The Email Deliverability Agency for DTC Brands That Want Their Emails Back in the Inbox
Deliverability isn’t an IT problem. It’s a revenue problem - when sender reputation breaks, every flow, campaign, and winback dies in spam before it can earn. We audit, repair, and protect it inside Klaviyo - the platform your revenue already runs on.



A Full Domain Migration. Zero Deliverability Disruption.
Heights outgrew yourheights.com. Moving an entire email program to a new domain is where most brands break flows, tank sender reputation, and lose revenue. YOCTO ran the whole migration - infrastructure, a 30-day staggered warmup, and a post-switch audit - with zero inboxing issues and a domain reputation strong enough to scale.
Read the full case study →Your List Didn’t Stop Caring. Your Emails Stopped Arriving.
Deliverability failures are invisible by design - Gmail doesn’t send you a note when it starts routing you to spam. When revenue-per-send slides, it’s almost always one of these.
Your opens halved and nobody can tell you why.
One month your campaigns did 40% opens. Now they do 15%. And your agency’s answer is ‘try a different subject line.’ The problem isn’t the copy. It’s where the email lands.
Gmail buries you in Promotions. Yahoo buries you in spam.
Your best customers aren’t ignoring you - they’re not seeing you. And once complaint rates cross Google’s 0.3% ceiling, the slide from Promotions to spam is fast and quiet.
Your wellness claims trip filters your agency has never heard of.
Supplements, beauty, femtech - words that are fine on your website get your emails junked. The filter won’t tell you which ones. Your open rate will, three months late.
Shared pool or dedicated domain? You’re guessing.
Klaviyo gives you three levers - shared IP pools, its shared klaviyomail.com domain, or a branded sending domain of your own. The right one depends on volume and history, and guessing wrong costs months of reputation.
Microsoft now rejects unauthenticated senders. Outright.
Since May 2025, Outlook and Hotmail bounce non-compliant bulk senders with a 550 error - not spam-folder them, reject them. If your SPF, DKIM, and DMARC setup predates the rule, part of your list is simply unreachable.
Your ‘engagement’ is part bots, part ghosts.
Bot clicks inflate your metrics while dead addresses drag your reputation down. You’re making sending decisions on data that lies to you.
Deliverability, Fixed Where Your Revenue Lives: Inside Klaviyo.
Generic deliverability consultants hand you a PDF and leave. We fix sender reputation inside the same flows and campaigns that make you money - because inbox placement isn’t the goal. Repeat revenue is.
Deliverability Audit & Diagnosis
A full teardown: SPF, DKIM, and DMARC alignment, sender reputation, placement testing, list-quality forensics, and a Klaviyo infrastructure review - shared pool or dedicated domain, answered with data instead of guesswork.
Repair & Warm-up
The audit’s fix list, executed in order: authentication repairs, domain and IP warm-up sequencing, suppression strategy, and content-filter fixes for regulated verticals like supplements and wellness.
Protection & Monitoring
Deliverability doesn’t stay fixed on its own. Sending-cadence design (smart sending), complaint-rate management under Gmail’s 0.3% ceiling, and ongoing placement monitoring - built into your retention program, not sold back to you as a separate tool.
Your Free Audit Is a Complete Gameplan, Not a Sales Call.
Most agencies sign you, then disappear for eight weeks to “audit” before they tell you anything. We do the opposite. Before you pay a cent - before you even decide - you get a full teardown of your account and the exact plan to fix it, built from your real numbers. Here’s what lands in your inbox.
A Full Unit Economics Analysis
We pull your real numbers from Shopify and Klaviyo - margins, breakeven, retention order by order, and the most you can spend to acquire a customer without losing money. You see exactly where the business makes money and where it leaks.
Every Growth Lever, Mapped
The full set of levers that move LTV - converting one-time buyers to subscription, cutting voluntary and failed-payment churn, reactivating cancellers, lifting subscription AOV. You see which ones actually move the needle.
A Prioritized Lifecycle Scorecard
A flow-by-flow benchmark of your current program - what’s working, what’s broken, what’s missing - scored against brands like yours and ranked by revenue impact. A number, and a reason.
The Complete Gameplan
One prioritized roadmap - which flows to fix, kill, or build, which subscriber segments to split out, and which subscription levers to pull, in order, with targets and trajectory. Not a 40-page deck. A plan you can start tomorrow.
All built from your live Klaviyo, Shopify, and subscription data - never a template.
Subject to availabilityNamed Clients. Real Numbers.
Proof We Didn’t Write Ourselves
Anyone can publish their own wins. These weren’t published by us. Klaviyo, Skio, Loop and others wrote up our clients’ results as their own customer success stories. Read them at the source.
The Founder Does the Diagnosis
George Kapernaros founded YOCTO to do one thing better than anyone else: turn DTC retention into a measurable system. He sits on the Klaviyo Partner Advisory Council, the Forbes Business Council, and the Fast Company Executive Board - and he personally runs the audit on every account before a single deliverable is complete.
The Videos Other Agencies Use to Train Their Staff



Email Deliverability Questions, Answered.
Bring Us Your Hardest Retention Problem.
We take on a fraction of the brands that apply - the ones we know we can move the needle for.






























