Customers Agencies · founders · AI-agent builders

312 agencies bill
their clients on NuMail.

The teams running outbound at scale don't want a tool — they want infrastructure they can resell. Here's who sends through their own mailboxes on NuMail, and the numbers they put their name behind.

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Trusted by outbound teams in 41 countries
AAnchor Collective
OOutbound Co.
RReply Lab
SSalt Studio
NNorthwind
CCypress Group
HHelix Bio
MMercer Group
BBluebird Logistics
FFoxtrot Capital
SSienna Health
PPinewood Labs
VVantage Reach
QQuarry SDR
LLoop & Co.
DDunmore Agency
▸ Case studies

One metric they'd put on a billboard.

Not vanity numbers. The operational thing that changed the day they moved their sending onto their own mailboxes.

O
Outbound Co.
Lead-gen agency · 23 clients
$27.2knet monthly payout, billed on their own Stripe
We were invoicing clients by hand and chasing payment every month. Stripe Connect onboarding took twelve minutes and we migrated 23 sub-workspaces in three days. Now it bills itself — we run a real SaaS, not a spreadsheet.
TR
Tomás Rivera
Founder · Outbound Co.
A
Anchor Collective
B2B SaaS · in-house team
2.4smedian reply-detection latency across the team
The reply detection is the unlock. A prospect replies and the Claude draft is sitting in our unibox before our AE has tabbed back to it. We went from same-day replies to same-minute, and our booked-call rate climbed 34% in a quarter.
SK
Sarah Kelleher
Head of Growth · Anchor Collective
R
Reply Lab
Agentic outbound · API-first
1.1Memails/month sent entirely through the API + MCP
We don't have a single human logging into a dashboard. Our agents create campaigns, enroll leads, and approve AI drafts over the MCP server. NuMail is the only platform whose API was clearly written for machines to drive, not just to demo.
DO
Dev Okafor
CTO · Reply Lab
S
Salt Studio
Outbound agency · 14 clients
+22%inbox placement after moving onto the warmup pool
Half our client domains were landing in Promotions. The cross-customer warmup pool fixed deliverability we'd been fighting for a year — real conversations from real mailboxes, not a bot net. Placement is up 22 points and our churn basically stopped.
MA
Maya Adler
Managing Partner · Salt Studio
▸ The whole network

Every number on this page rolls up to here.

4.2M
Emails sent every month through customers' own mailboxes
Gmail · Graph · SMTP
312
Agencies billing their end-clients on NuMail today
Stripe Connect · white-label
4.9/5
Average rating across G2, Capterra & Product Hunt
847 verified reviews
2.4s
Median reply detection, draft ready before you switch tabs
P50 · all providers
▸ In their words

The reviews we didn't write.

Pulled from G2 and Product Hunt. We left the typos in.

★★★★★
5.0 · Switched from Instantly
Owning the mailboxes instead of renting some pooled IP changed everything. Deliverability is night and day and I can actually explain to clients where their emails send from.
G2 · VerifiedAgency owner
★★★★★
5.0 · Founder, seed-stage
I run all of my outbound solo. The AI drafts sound like me, the unibox sorts the noise, and I approve replies from my phone between meetings. It's the first cold-email tool I haven't cancelled.
Product Hunt★ top pick
★★★★★
4.8 · Platform / RevOps
The REST API and MCP server are genuinely best-in-class for this category. HMAC webhooks, idempotency keys, cursor pagination — it reads like an infra product, not a marketing one. We built our whole sequencer on it.
G2 · VerifiedMid-market
Want the full write-ups? Read the customer stories on the blog →

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