Hands-on email infrastructure — not a self-serve SaaS

Give your marketing worries to us. Good things happen when we get involved.

ListWorker is a custom-fit email marketing service and a deep-dive deliverability practice, run by former postmasters and engineers from the largest email providers in the United States.

Contact us today → See how we work
We review every prospective sender. No mass sign-ups, no black-hat clients.
AI-narrated overview — 90 seconds Request the deep-dive →
30+ yrs
Operational deliverability experience
2,600+
Items checked in a full audit
100%
Audited clients found preventable issues
24 / 7
Block & deferral monitoring
Our story

A custom shop, not a shoebox.

Built by three postmasters and two engineers who came up inside the largest US email services. We don't fit you into a product — we fit our service to you.

Every marketer knows their deliverability is suffering. The spam folder exists for a reason — and you don't belong in it.

Most ESPs say "things are fine on our end" and bounce the issue back. They don't have the expertise to do the deep-dive. We do.

Our team has access to over 1,621 sites, blacklist services, reputation systems, and antispam platforms — including ISP-only services that require ASN-level credentials to even open a dialog.

The trick to fixing deliverability isn't usually the fix itself. It's knowing who to contact, how to phrase the mitigation request, what to do before contacting them, and what to expect after.

We've spent thirty years building the relationships, integrations, and monitors that make those conversations productive. That's what you're hiring.

What we do

Two services. Both run by the same people.

A deep technical audit of your existing setup, or a fully managed email platform you can switch to. Most clients start with the audit and stay for the platform.

Service 01

End-to-end deliverability analysis

A complete review of every system, header, and reputation signal touching your sending
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Think everything's fine? A lot of companies tell us their marketing operations are flawless. To date, 100% of clients we've audited had issues they hadn't found — some of them losing real money to the spam folder.

Public block monitors cover about 5% of what actually matters. We check the other 95% — ISP-private blacklists, reputation scorekeepers, FBL data, antispam image filters, DNS drift, header anomalies, neighbor reputation, and dozens of categories most operators have never heard of.

What we examine

  • 800+ blacklist / blocking services, public and ISP-private
  • 87 reputation scorekeeper systems
  • SPF, DKIM, DMARC, BIMI on live seed tests
  • DNS configuration, timing, redundancy, A-record drop-outs
  • 47-point content analysis — trap words, HTML accuracy, link endpoints
  • Full header analysis on every seed message sent
  • Light-pen security review — web server config, SSL certs, plug-ins
  • "Neighborhood" check — who else lives on your IP / network
  • Image / HTML scoring across Barracuda, BitDefender, McAfee, etc.
  • 24-month reputation lookback at major blacklists
  • "Message vanishing" seed tests — silent drops by ISPs
  • The classic BOM issue (30% of senders have it — we'll show you)
Quick scan
$595/ one day

Fast, in-depth review of domain & IP reputation plus core technical configuration. 530+ checks over 24 hours. Most clients use this to test how we work.

Full audit
$2,995/ one week

Time to actually watch your mailings perform. 1,630 data points across blacklists, reputation, ISP-private lists, and full technical configuration analysis.

Deep dive
$9,995/ one month

"Turn over every stone." For publishers, retailers, and any operation where every percentage point of inbox placement is real revenue. Everything plus full digital marketing review.

Service 02

The ListWorker marketing platform

A custom-fit ESP that adapts to your workflow — not the other way around
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The big-name ESPs hand you a rigid product and tell you to make your business fit inside it. We built our platform from scratch with hooks in place to plug in any custom feature you need — integrations, data flows, reporting cuts, custom fields, the works.

And if a feature doesn't exist yet? We'll build it for you. Free.

Free dedicated IPs

Start with 4 dedicated IPs at no extra cost. Scale up as your volume grows.

Flat-rate pricing

Lower than any quality service we've benchmarked against. No surprise overage fees.

Unlimited everything

Lists, accounts, users, sub-accounts. Build the org structure your team actually has.

24/7 monitoring & mitigation

Block detection, deferral handling, whitelist maintenance, DNS change alerts — running around the clock.

Series & trigger automation

Up to 30 days of messaging in a series, plus event-triggered sends and remote push/pull data flows.

Real human technicians

When deliverability gets weird, you reach the people running the platform. No tier-one routing.

Your data is yours

Full export of opens, clicks, bounces, complaints, subscribers, unsubscribers. No friction-as-lock-in.

Custom integrations

If your stack needs something specific, we'll plug it in. Most requests are no charge.

Up and running fast

24–36 hours from contract to first send. Some clients are mailing within 6 hours.

The fastest way to evaluate us: tell us what platform you use today, what you like, what you don't, and what you wish it had. We'll show you our equivalent and what it would take to build the rest. Read some success stories.

Important — we don't take everyone

We review you before we accept you.

About 15% of email marketers operate in a way that has already exhausted ISP patience — mishandled complaints, ignored unsubscribes, completely cold lists. If we find the ISP community is already furious with your sending, we'll politely decline.

Even good-faith operators who have "seen the light" sometimes can't be helped. Once reputation crosses a tipping point, the doors close and they're hard to reopen. The earlier we look, the more we can do.

Let's talk

You have questions. We have answers.

Pick the right inbox or call us. Every message gets a real human response, fast.

Email us

Or call us

(646) 480-7890

AI-routed call system — sends your inquiry directly to the right department.

Open an account Request the deep-dive video