We'll build or rebuild your email & SMS retention system, 100% done for you

One-time payment · No monthly retainer · Yours to keep

The guarantee

A 5x ROI within 60 days, or we beat your current setup by 20%. Miss both and you don't pay, and we hand you an extra $1,000 for wasting your time.*

* The fine print, in plain English

— The whole system, in 15 minutes —
Book a Call →
return address: the dead letter office

We recover the
money you left
for dead.

We're an email and SMS agency for e-commerce brands. We've turned unengaged subscribers, warm leads, and forgotten customers into over $100M in recovered revenue that would have otherwise gone down the drain.

$100M+
Revenue recovered
100+
7-to-9-figure brands
43x
Avg ROI, first 60 days
— Drag to see more —
Chef's Kiss welcome email design
Flexy Joints product email design
Peace Out Skincare email design
Real Handful email design
Denali Canning email design
Pumps flavors email design
Hydrohealth subscription email design
Laundry Labs welcome email design
Brands we've delivered for
Boxbollen Athlean-X Chip Cookies Western Bagel Dandy ReyterMD Prime Peptides Chef's Kiss Boxbollen Athlean-X Chip Cookies Western Bagel Dandy ReyterMD Prime Peptides Chef's Kiss
// Case files

Proof of delivery

Four files pulled straight from the archive. Open any of them for the full breakdown: the goals, the work, the emails, and the numbers that moved.

001
Case File No. 001 · Electric Motorcycles
GritShift: 25x ROI in the First 60 Days

No flows, no retention system, nothing set up. We built the whole infrastructure, and total revenue grew 22% in the same window.

Open the Case File →
002
Case File No. 002 · Rope & Cordage
SGT Knots: 41x ROI in the First 60 Days

Took over another agency's minimal setup, beat their flows by 73%, and total revenue rose 32% over the period.

Open the Case File →
003
Case File No. 003 · Hydration & Wellness
HydroHealth: 63x ROI in the First 60 Days

Rebuilt pre-purchase, built post-purchase from nothing, beat the old setup by more than 100%, and revenue climbed 16%.

Open the Case File →
004
Case File No. 004 · Health & Fitness
Athlean-X: 51x ROI in the First 60 Days

Full infrastructure plus an SMS launch for a 20-year fitness giant. Previous setup beaten by 47%; revenue up 15%.

Open the Case File →
Browse all case files →
// The problem

Most brands treat their list like a mailbag nobody sorts.

Subscribers go quiet. Flows go stale. Campaigns turn into "10% off" on repeat until people stop opening out of self-defense.

And here's the uncomfortable part: prettier emails won't fix it. Design and copy have been commoditized. Templates are cheap, AI writes passable copy, and every agency portfolio looks the same. The real money moved upstream, into strategy and data: who to send to, when, with what offer, and what to do the moment they stop opening.

Which is why the job title matters less than the job. We're an LTV improver. A churn reducer. An MRR increaser. Email and SMS are simply the sharpest tools for it. Ours also happen to look and read better than anyone else's.

Unclaimed revenue is still revenue.
We go get it for you.

ROI on the setup, first 60 days
Four real accounts, straight from the case files
GRITSHIFT Gritshift: 25x ROI in the first 60 days 25x SGT KNOTS Sgt Knots: 41x ROI in the first 60 days 41x ATHLEAN-X Athlean-X: 51x ROI in the first 60 days 51x HYDROHEALTH Hydrohealth: 63x ROI in the first 60 days 63x
Across 100+ accounts, the average is 43x
100+
7-to-9-figure brands served
$100M+
Revenue generated by email & SMS
40%+
Of revenue from Klaviyo, consistently, for managed clients
43x
Avg ROI, first 60 days
Book a Call →
// The route

What happens after you book

Every account runs the same route. Here's what actually gets done, in order.

Stop 01

The Autopsy

A full account audit: flows, deliverability, segments, past sends. We find where the revenue died and why.

Stop 02

The Strategy & Research

A revenue map built from your data: who to mail, when, and with what offer. Plus full-on company research: your customers, your competitors, your category. We become an expert in what you sell and who you sell it to.

Stop 03

The Core Flows

Pre-purchase and post-purchase: welcome, abandonment, post-purchase, winback. Written, designed, and built in Klaviyo. This is the always-on machine.

Stop 04

Watch the Results Come In

First sends go live in days, not months. The flows start firing, the dashboard starts moving, and we tune the system as the numbers climb.

The clock
Days 1–3First deliverables in your account
Days 3–4First sends & flows live
Week 2Every foundational flow live
Day 30+The system compounds
Setup first. Results fast. Start your setup →
First Class · Dead Letter Office · Par Avion
// Services

The system we build in your account

The traffic at the top is yours. Everything below the dashed red line is what Dead Letter strategizes, writes, designs, and ships.

Paid ads Organic & social Content Your website YOUR TRAFFIC ↑ BUILT BY DEAD LETTER ↓ Opt-in offerspopups & list growth THE LIST EMAIL FLOWS Welcome×5–8 emails Site abandon×2–3 Browse abandon×3–4 Cart + checkout×4 Post-purchase×4–6 Cross-sell×2–3 Upsell×2–3 Replenishment×2–3 Review & referral×2–3 VIP recognition×2–3 Winback×3–4 Sunset×2–3 SEQUENCE LENGTHS TUNED TO YOUR CATALOG AND PRICE POINTS SUBSCRIPTION FLOWS Subscription upsell×2–3 Renewal reminders×1–2 Cancellation save×1–2 Churn recovery×2–3 SMS FLOWS Welcome series×2–3 texts Abandonment series×2–3 texts Winback series×2 texts Customers Repeat customers THE LTV LOOP
Under every stage: in-house design & copy
// Why us

Why brands trust us with their email list

1
Sorted

Email and SMS only

We do one thing, so we're dangerous at it. No "full-funnel" hand-waving, no juniors learning on your account.

2
Stamped

Speed

Deliverables go live within 1 to 3 days of kickoff. The variable isn't us, it's how fast you get us revisions and approvals. Your list starts working while other agencies are still onboarding.

3
Sealed

Full transparency

Weekly reporting and direct Slack access. You always know what shipped, what it made, and what's next.

4
Signed

No lock-in

We set up for a one-time payment, then you decide if you want to keep working with us on a month-to-month engagement. Our retention strategy is results, not long-term contracts that lock you in.

5
Delivered

Flows built as assets, not deliverables

Our flows aren't templates with your logo dropped in. They're custom revenue assets: researched against your customers and competitors, written and designed to your catalog, and built on segmentation that's proven itself across 100+ accounts. They live in your account and keep firing whether we stick around or not. You keep everything, forever.

// The TLDR

Dead Letter vs. everyone else's agency

If you only read one section on this page, read this one.

Most agenciesDead Letter
Focus Email, ads, SEO, TikTok, whatever pays Email and SMS. That's it. That's the craft.
Who runs your account A junior pod behind an account manager A senior team, with the founder's hands in every account
Design & copy Recycled templates, outsourced words Custom, in-house, in your brand's voice
What gets reported Opens, clicks, and vibes Revenue, LTV, churn. What your P&L cares about.
Strategy Templated flows installed once, forgotten forever Flows researched, custom-built, and proven across 100+ accounts
Contracts 6 to 12 month lock-ins One-time setup. Continue month to month only if the results earn it.
// The math

This isn't a cost. It's the best trade you'll make.

Put a dollar in, get more than a dollar out, and it stops being an expense. Our average client sees a 43x ROI in the first 60 days of working with us. If we can't find that math in your account, we'll tell you on the first call and part as friends.

And it's guaranteed: a 5x ROI on your investment within 60 days, or we outperform your current setup by at least 20%. Miss both and you don't pay, and we hand you an extra $1,000 for wasting your time.

Run the Math on a Call →
// Verified client reviews

Signed, sealed, on the record.

"Riley has been fantastic to work with. Great communicator, hard working, fast and efficient. He built our entire Klaviyo email system, including copy and design. I plan on working with him in an ongoing manner for this brand, and will use him for others in the future. 10/10!"

✓ Verified client ↗
Dan Aziz
Dan Aziz
Founder, Skoka Pouches

"Riley is an exceptional email designer who combines creativity, attention to detail, and technical expertise to deliver high-quality, visually stunning campaigns. He is professional, communicative, and always meets deadlines, making him a fantastic freelancer to work with. Highly recommend!"

✓ Verified client ↗
Justin Kunimoto
Justin Kunimoto
Marketing Manager, Levendi Winery

"Riley was invaluable in helping Tunelark professionalize our email marketing function... he built our first high-polish HTML emails, and he helped us develop an email production pipeline that Tunelark continued to use... Riley was proactive, communicative, adaptable, and highly responsive to feedback. He was also a joy to work with on a personal level. We highly recommend him."

✓ Verified client ↗
Aaron Clayton-Dunn
Aaron Clayton-Dunn
Founder, Tunelark

"From the moment we started our collaboration Riley demonstrated a deep understanding of our industry and a remarkable proficiency in email marketing... His dedication to optimizing our campaigns has translated into tangible results, with impressive open and conversion rates... His contributions have been instrumental in our success, and I look forward to continuing our fruitful partnership."

✓ Verified client ↗
Josh Vee
Josh Vee
CEO, GritShift

"Riley helped with list management & copywriting for our array of products. He helped sell our info products, live events, and high ticket coaching programs - the results were nothing short of spectacular... The email content was compelling and resonated deeply with our target audience, resulting in unprecedented engagement and conversions."

✓ Verified client ↗
Bill Pipes
Bill Pipes
CEO, G3 Coaching

"Very knowledgable team with a very laidback demeanor which I appreciated yet I knew he would get shit done. Fully endorsed."

✓ Verified client ↗
C
Curt
CEO, Concrete Tools Direct
Riley Strader, founder of Dead Letter, mid-shrug in the desert in front of a Joshua tree

Pictured: the founder explaining list segmentation to a Joshua tree. It still hasn't opted in. We respect that.

// The founder

Meet your postmaster

I'm Riley Strader. I started as an account manager at one of the fastest-growing agencies in the US, then went freelance and built my own roster from scratch. After reaching the top 3% of email and SMS marketing talent platform-wide on Upwork, it was time for the next step: the agency route.

I'm fortunate to have more work than I know what to do with, so Dead Letter was born out of personal demand for my services. I've built a team I trust, and I still keep my hands in every account we take on. When you hire Dead Letter, my name is on the work.

R. Strader · Sandy, Utah
// Free training

Steal the playbook

Free trainings from the Dead Letter desk. Take them, use them, and hire us when you'd rather not do it yourself.

// FAQ

Questions, answered

We already have flows. Do you rebuild or optimize?
Rebuild. Optimizing a system built on outdated strategy is polishing the wrong thing. We architect from scratch using your data, then build. And the guarantee reflects it. If you already have something running, ours has to beat it by at least 20% inside 60 days or you don't pay.
How long until we see revenue?
Your sign-up forms and first flows are live within days, and those earn immediately. The full system is in place within 2 to 3 weeks. The 60 day guarantee clock starts when everything goes live, not when you sign. Flows earn on a lag and I'm not going to run a timer on work that isn't running yet.
How much work is this on our end?
You approve and leave comments as we send things over. We own research, strategy, copy, design, build and QA. The one thing we need is a fast approval turnaround. A build that sits in review for three weeks stops being a 60 day guarantee.
What does it cost?
Four figures, and the exact number depends on how many of the 19 systems you're missing, whether SMS is in scope, and how complex your catalog is. That's why I won't quote before I've seen the account. If four figures toward the one asset that runs on its own forever isn't something you can absorb right now, this isn't the right time, and I'd rather you know that here than on a call.
How does the guarantee work?
Two tracks, depending on where you're starting. If you have nothing set up, we guarantee a 5x ROI on your investment within 60 days of the system going live. If you already have flows running, we guarantee ours outperforms your current setup by at least 20% in the same window. Miss the mark that applies to you and you don't pay, plus we hand you an extra $1,000 for wasting your time. One qualifier: the full guarantee applies to stores doing $75k a month or more, because below that there isn't enough traffic to promise those numbers and mean them. We put the exact terms in writing before kickoff so there's never any ambiguity.
What size brand is this for?
Ecommerce brands doing at least $75k a month qualify for the full guarantee. We work with brands under that too, they just don't qualify, because below that volume there isn't enough traffic for me to promise 5x in 60 days and mean it. I'll tell you which side of that line you're on before you pay anything.
Why not just get flows built cheap?
A cheap build gives you emails. This gives you a system architected from your own retention data, tested across 100+ accounts, with the segmentation and logic that actually decide whether flows perform. And nobody building cheap is offering you guaranteed results like we are. They guarantee project completion, not results from it.
Do you actually do SMS, or is it just email?
Both, in the same build. Same strategy, same segments, same team. Email without SMS runs at half coverage, which is why it's on the list of 19 rather than sold to you as an upgrade.
Is it built in Klaviyo?
Klaviyo or Omnisend, whichever you're on, with your subscription and SMS platforms integrated as needed. It's built inside your account, on your domain, with your data. It stays there whether or not we keep working together.
What if we don't like the copy or design?
We get on a call and work it out, same day if it matters. I head strategy on every account personally, so you're not relaying feedback through an account manager to someone you've never met. Pushback is how we dial into your brand faster.
Do you use AI?
Not for a single word of copy or a single email design. For analysis, where it beats a spreadsheet, yes. Your competitors are all using it to write. The inbox is a relative game, and when every email in that folder sounds like the same helpful robot, sounding like an actual person is the entire advantage.
How do we know it worked?
We baseline your flow revenue, list growth rate and repeat rate at day 0, and report against it. The guarantee is built on ROI and incremental revenue, not attributed revenue, and we agree on the exact measurement in writing before we start. Attributed revenue is a settings change. ROI isn't.
What happens after the build?
Nothing has to happen. It's yours, it's in your account, and it keeps running. If you want us managing it after, that's month to month with no long-term contract. We keep clients with results, not lock-ins.
What if our product doesn't have repeat purchase?
There are ways to manufacture retention around a low-repeat product, like accessory lines and a rewards program, but it'll never work as well as natural product inertia. Regardless, would be happy to take a look.
How are you different from other email agencies?
A few things stack up. We only do email and SMS, and everything is built in-house: strategy, copy, design, and implementation. The founder has his hands in every account. Deliverables are never cookie-cutter and the scope is unlimited when the data backs it. Turnarounds are measured in days, terms are month to month, and the work is guaranteed: 5x ROI in 60 days, or 20% over your current setup, or you don't pay. Most agencies can't say one of those. We can say all of them.
How many campaigns per month?
Unlimited, for managed clients. Twice a week? Great. Daily? Great. The volume has to be backed by data. We don't do extra work for fun, and we don't cap work that's earning.
Return to sender? Not anymore.

Your list has unfinished business.

One call. We'll look at your account and tell you exactly where the dead revenue is. If we can't find any, we'll tell you that too.

Book a Call →
Guaranteed: 5x ROI in 60 days, or 20% over your current setup, or you don't pay + $1,000 for your time