Deliverability first
Every feature we ship is judged by one metric — did it land in the inbox. No vanity, no fluff.
Our storyOperators building the
Operators building the
outreach engine they always wanted.
Sendlio was founded by operators who ran cold email campaigns daily — and got burned by every other cold email tool on the market. So we built the cold email software we actually needed. Then opened it up to 279+ growth teams across 25+ countries.
Our mission
Make outreach work — for teams that can't afford bounces, spam folders, or clunky tools. One engine. One outcome: inbox.
Powering outreach at 279+ scaling teams
Stripe
segment
intercom
Dropbox
Framer
Notion
GitHub
slack
Linear
▲ Vercel
Stripe
segment
intercom
Dropbox
Framer
Notion
GitHub
slack
Linear
▲ Vercel
279+Growth teams
120K+Emails / mo
99%Inbox placement
25+Countries
The vision
Cold email isn't dead. Bad tools are.
A great outreach engine identifies the right prospects, protects your reputation, ships personalized sequences at scale, and surfaces what's working — without you babysitting it.
That's the engine we built. And we're only getting started.
What we stand for
Three values. Every decision.
Operator-built
We built Sendlio because we ran outbound ourselves and hated every tool. Every flow is shaped by real sales workflows.
Radical transparency
Honest pricing. Honest metrics. Honest roadmap. We'd rather lose a deal than ship dark patterns.
Journey
From scrappy startup to outreach engine.
2024
Founded
Redlio Designs starts building Sendlio — the outreach engine we always wanted.
2025
Private beta
First 100 teams onboard. Warmup network, unified inbox, and analytics live.
2026
Public launch
279+ teams shipping outbound. AI personalization and integrations ship.
Next
What's coming
SOC 2 Type II certification, deeper CRM integrations, and 1,000-team scale.
4.9 / 5 · 120+ reviews
Trusted by teams that ship outreach for a living.
"Sendlio is by far the best outreach tool I have ever used. It's reliable, smart, and saves us hours every week."
Sofia Lindstrom
Marketing Consultant
"Since integrating Sendlio, our campaigns have become 10× more efficient. It's smooth, powerful, and doesn't require babysitting."
Luca Moretti
Growth Strategist
"Our agency manages 10+ domains. Sendlio keeps them warm and healthy without lifting a finger. Honestly, it's the best tool we didn't know we needed."
Mateo García
Founder, MailForce
"We stopped worrying about domain reputation after switching to Sendlio. It works in the background and keeps our emails out of spam."
Sam Sen
General Manager
"With Sendlio, cold emails finally reach inboxes — no fluff, no spam. Clean, reliable, and ready for serious senders."
Sarah Sen
Operations Lead
"Sendlio's automation takes care of inbox health so we can focus on outreach. Super easy to use and surprisingly powerful under the hood."
John D'Crouze
B2B Growth Advisor
Common questions.
Still curious? Talk to our team.
AES-256 encryption at rest, TLS 1.2+ in transit. SOC 2 Type II in progress. GDPR and CCPA ready. Your contact lists are never used for training or shared with third parties.