AI Outbound Agent

Your sales rep
never sleeps.

ColdStack is an AI agent that runs your entire outbound pipeline — finds leads, writes cold emails, sends, follows up, and reports results. Around the clock. No headcount.

3.2M+
emails sent this month
23%
avg reply rate
$0
salary, benefits, or PTO
One prompt → ICP + 100 leads + sequence in <90s →
Live outbound feed
SR
Sarah Reeves
Head of Growth @ Lattice
Sent
"Hi Sarah, noticed Lattice just raised Series C. Congrats! Most growth teams your size struggle with outbound at scale — we have a fix..."
Sent 2 min ago · 847 leads in queue
MC
Marcus Chen
VP Sales @ Notion
Reply
"Marcus — most VP Sales I talk to say their biggest bottleneck is research, not writing. We auto-research every prospect before the first email. Worth 15 min?"
Reply 8 min ago · This week: 23% reply rate
JP
Jamie Park
Founder @ Clay
Research
Scanning: LinkedIn, Crunchbase, G2, Hunter.io
Researching now · ICP match: 94%

The full outbound loop.
Autonomous.

01

Define your ICP

Tell ColdStack who you're targeting — industry, company size, title, funding stage. It builds a target list and keeps it fresh.

02

Research every lead

Before each email, ColdStack reads your prospect's LinkedIn, recent news, job postings, and any public signal. Then it writes to that.

03

Send & follow up

Personalized emails go out daily from your own domain. ColdStack follows your cadence — 3 days, 7 days, resend with new angle.

04

Report what matters

Daily digest: opens, replies, meetings booked, pipeline generated. You review the replies; ColdStack handles everything else.

Everything an outbound
SDR does. Better.

Watch it run.

Defining ICP...
ICP Defined
VP Sales, Enterprise SaaS, 50-500 employees
done
Prospects Found
247 leads matched · Acme Corp, Notion, Lattice
done
Personalized
"Hi Jordan — saw Lattice raised Series C..."
done
Sent
89 emails delivered · yourdomain.com
done
Replies Classified
23 replies · 8 positive · 5 questions
done
Meeting Booked
3 calls scheduled · Cal.com links sent
hot

Free during beta.

We're building in public. No paid tiers until the product is rock-solid. You get the full platform, we get honest feedback.

Early Access
$0
during beta
  • Unlimited leads & campaigns
  • AI personalization on every email
  • Multi-mailbox rotation + warmup
  • Reply triage + auto-drafts
  • Meeting booking via Cal.com
  • Weekly digest reports
  • A/B testing on sequences
Start for free

No credit card. No catch. Cancel anytime.

Used by founders shipping
outbound without an SDR.

Founder, Early-Stage SaaS
Head of Growth, Series A
Solo Founder, Bootstrapped

"Set it up in 20 minutes. First reply came in 2 hours."

— Alex M., Founder @ Kaption

"I was skeptical. Then I got 6 qualified replies in week one."

— Sarah K., Head of Growth @ Relay

"No SDR. No agency. Just ColdStack running outbound while I slept."

— Tom W., Solo Founder

Write once. Personalize at scale.

Other tools give you templates. ColdStack gives you a writing system — it reads every prospect's public footprint and writes every email fresh. Not a mail merge. Not a template. A real message that happens to be written by AI.

Hyper-personalization, automatic

Your domain. Your reputation.

ColdStack connects to your email account — it sends from your inbox, using your domain, with your warmup and reputation profile. Deliverability stays clean because it's real email, not a separate sending domain.

Gmail / Outlook / custom SMTP
you@yourcompany.com — warming up, day 3
ops@yourcompany.com — active, 142 sent this week
founders@yourcompany.com — cooldown, resuming in 2 days
Reputation score (30-day avg)

Follow-up sequences that actually work.

Most sequences are a 3-email chain that everyone ignores. ColdStack builds multi-step cadences with genuine variation — different angles, different subject lines, different times of day. If no reply after 5 touches, it flags the lead as cold and moves on.

Auto-pause, auto-resume, smart rotation
Current campaign: "Enterprise SaaS — VP Sales"
Day 0
Email — personalization angle: recent funding
Sent
Day 3
Email — angle: competitor mention
Sent
Day 7
Email — angle: mutual connection
Waiting
Day 12
LinkedIn — connection request + note
Queued
Day 18
Email — final: "last try" framing
Queued

Numbers, not promises.

$47K
pipeline generated in 30 days
"We booked 14 demos from a cold list of 800. I didn't write a single email."
— Priya Nair, Founder @ Foldwise
23%
reply rate, every week, on autopilot
"Industry average for cold email is 1-3%. ColdStack consistently hits 20+. I've checked."
— Tom Whitfield, Head of Growth @ Relay
0
hours spent on outbound per week
"I set the ICP on a Monday. By Friday I had 6 qualified replies. Spent 10 minutes reviewing them."
— Dan Kowalski, Solo Founder @ Stackline

The outbound problem isn't writing.
It's everything before the first word.

Every sales team has someone who "could do outreach if they had time." Nobody has time. So outreach doesn't happen, or it happens badly — mass-sent templates that everyone ignores, research that never gets done, follow-ups that slip through the cracks.

ColdStack was built for the founder who's thought about outbound a hundred times, done it for two weeks, and given up. It runs the whole thing. You review the replies.

"We built the employee we couldn't afford to hire."