Proven Inbox Placement Rate
More Replies Than Manual Outreach
Emails Delivered to Primary Inbox Monthly
Accounts Warmed Up & Protected
2,000+ Sales Teams Trust ColdBox
Every Feature Built to Fill Your Pipeline
Send 525,000+ emails per month with 95%+ inbox placement. Built for teams that need proven deliverability and instant scalability.

Close Deals Faster with Instant CRM Sync
Automatically push every interested lead into HubSpot, Salesforce, or Pipedrive the instant they reply. Zero manual data entry.
Book 2x More Meetings on Autopilot
AI Reply Agents handle objections, answer questions, and book Calendly meetings automatically. Choose full autopilot or approve each reply with one click.

Scale to 500K+ Emails Without Domain Risk
Connect unlimited email accounts and safely scale from 1,000 to 525,000 emails per month with automated reputation protection.

Know Exactly What's Working in Real Time
Instant dashboards for open rates, click-throughs, and bounces. Optimize campaigns on the fly, not days later.

Protect Your Domain, Guaranteed
Automated health monitoring, warmup analytics, and deliverability optimization keep your sender score high and your emails out of spam.
Go From Zero to Booked
Meetings in 3 Steps
Most teams launch their first campaign within 5 minutes. No technical setup required — just connect, personalize, and start booking meetings.
Connect & Upload
Link Gmail or Outlook in one click and upload your leads. Our built-in verifier guarantees 0% bounce rates before you send a single email.
Craft Your Campaign
AI generates hyper-personalized subject lines and body copy for every prospect. Teams see 3x higher open rates versus generic templates.
Launch & Book Meetings
Hit send and let AI Reply Agents handle the rest. Automated follow-ups, instant reply handling, and real-time analytics — all on autopilot.
Triple Your Reply Rates with Proven Outreach Tools
Free built-in warmup, automated sequences, and a unified inbox — everything you need to turn cold emails into booked meetings.

AI That Works While You Sleep
Five proven AI engines that instantly score leads, optimize send times, prevent spam, generate unique variations, and classify every reply — fully automated, zero manual work.
Why 2,000+ Teams Switched to ColdBox
More emails, better warmup, AI reply agents, and real-time inbox sync. See why ColdBox outperforms Instantly and SmartLead on every metric that matters.
ColdBox
Instantly
SmartLeads
Land in the Primary Inbox, Every Time
Five proven tools that guarantee your emails reach the primary inbox. Monitor, protect, and optimize deliverability before every send — the reason our users see 95%+ inbox rates.
Know Where You'll Land Before You Send
Test against real Gmail, Outlook, and Yahoo seed accounts before every campaign. See exactly whether you'll hit Primary, Promotions, or Spam — and fix issues before they cost you deals.
Send More Without Burning Accounts
Automatically rotate sending across all your email accounts using health-score-weighted selection. Each account stays within safe limits while your total volume scales effortlessly.
Fix Domain Issues in One Click
Instantly validate SPF, DKIM, and DMARC records and get step-by-step fix instructions. Prevent misconfigurations from silently destroying your deliverability.
Boost Click-Through Rates with Branded Links
Replace generic tracking links with your own branded domain. Prospects trust branded URLs more, and you avoid shared-domain blacklisting that kills deliverability.
Instant Blocklist Alerts Before Damage Spreads
Real-time monitoring against every major email blocklist. Get instant alerts the moment any sending domain or IP is flagged, with step-by-step remediation to restore deliverability fast.























Automate Everything Beyond the Send
Eliminate manual data entry forever. Bi-directional CRM sync, automated reports, and a full REST API keep your entire revenue stack running on autopilot.
Two-Way CRM Sync
Every open, reply, and booked meeting is instantly logged to your CRM — zero manual entry, zero missed updates. Salesforce, HubSpot, and Pipedrive sync in real time with bi-directional field mapping so your pipeline is always accurate.
- Instant bi-directional sync with major CRMs
- Auto-log every open, reply, and booked meeting
- Custom field mapping for your exact workflow
Scheduled Reports
Know exactly what's driving revenue without lifting a finger. Automated PDF or Excel campaign reports arrive in your inbox daily, weekly, or monthly — with built-in visitor tracking to see which leads hit your site after opening.
- Automated PDF and Excel reports delivered to your inbox
- Daily, weekly, or monthly — set it and forget it
- Website visitor tracking tied to individual leads
Webhooks & API
Build any custom integration your team needs. 20+ webhook event types with HMAC-signed payloads and automatic retry logic, plus a full REST API for programmatic campaign management at scale.
- 20+ secure event types with HMAC signatures
- Automatic retry with exponential backoff — never miss an event
- Full REST API with managed keys for unlimited customization
Start Free. Scale as You Grow.
No hidden fees. No per-seat charges. Every plan includes free warmup, unlimited email accounts, and AI-powered deliverability. Start with a free trial — no credit card required.
2,000+ Teams. Millions of Emails. Real Results.
See why sales teams are booking 2x more meetings and generating 312% more replies after switching to ColdBox.
Marcus Chen
"ColdBox completely changed our outreach game. We went from 2% reply rates to over 12% in just three weeks. The email warmup feature alone is worth the price."
Jan 8, 2025
Sarah Mitchell
"The AI Reply Agents are a game-changer. They handle objections and book meetings on autopilot while I focus on closing deals. We've doubled our booked calls."
Feb 22, 2025
James Rodriguez
"We connected HubSpot and Salesforce in minutes. Interested leads get pushed straight into our CRM pipeline automatically. The integration was seamless."
Dec 14, 2024
Priya Sharma
"The real-time analytics dashboard gives us instant visibility into open rates, replies, and bounces. We optimize campaigns on the fly instead of waiting days for data."
Mar 5, 2025
David Kim
"We scaled from 5,000 to 200,000 emails per month without a single deliverability issue. ColdBox's warmup and sender reputation tools kept us in the primary inbox."
Nov 30, 2024
Marcus Chen
"ColdBox completely changed our outreach game. We went from 2% reply rates to over 12% in just three weeks. The email warmup feature alone is worth the price."
Jan 8, 2025
Sarah Mitchell
"The AI Reply Agents are a game-changer. They handle objections and book meetings on autopilot while I focus on closing deals. We've doubled our booked calls."
Feb 22, 2025
James Rodriguez
"We connected HubSpot and Salesforce in minutes. Interested leads get pushed straight into our CRM pipeline automatically. The integration was seamless."
Dec 14, 2024
Priya Sharma
"The real-time analytics dashboard gives us instant visibility into open rates, replies, and bounces. We optimize campaigns on the fly instead of waiting days for data."
Mar 5, 2025
David Kim
"We scaled from 5,000 to 200,000 emails per month without a single deliverability issue. ColdBox's warmup and sender reputation tools kept us in the primary inbox."
Nov 30, 2024
Emily Torres
"The Unified Inbox is incredible. Managing replies from 15 email accounts in one dashboard saved our SDR team hours every day. No more switching between inboxes."
Jan 19, 2025
Alex Novak
"Setting up smart sequences with A/B testing and subsequences was so intuitive. Our follow-up campaigns now trigger automatically based on reply sentiment."
Feb 10, 2025
Rachel Patel
"We tried Instantly and SmartLead before switching to ColdBox. The AI agents and premium warmup are features you simply can't get anywhere else at this price."
Dec 3, 2024
Michael Foster
"Their customer support is exceptional—quick, responsive, and truly helpful. They helped us set up our entire cold outreach workflow in under an hour."
Mar 1, 2025
Nina Johansson
"The Human-in-the-Loop mode for AI agents gives us the perfect balance. AI drafts the reply, we approve it with one click. Quality stays high while response time drops."
Jan 28, 2025
Emily Torres
"The Unified Inbox is incredible. Managing replies from 15 email accounts in one dashboard saved our SDR team hours every day. No more switching between inboxes."
Jan 19, 2025
Alex Novak
"Setting up smart sequences with A/B testing and subsequences was so intuitive. Our follow-up campaigns now trigger automatically based on reply sentiment."
Feb 10, 2025
Rachel Patel
"We tried Instantly and SmartLead before switching to ColdBox. The AI agents and premium warmup are features you simply can't get anywhere else at this price."
Dec 3, 2024
Michael Foster
"Their customer support is exceptional—quick, responsive, and truly helpful. They helped us set up our entire cold outreach workflow in under an hour."
Mar 1, 2025
Nina Johansson
"The Human-in-the-Loop mode for AI agents gives us the perfect balance. AI drafts the reply, we approve it with one click. Quality stays high while response time drops."
Jan 28, 2025
Got Questions? We Have Answers.
Everything you need to know before launching your first campaign. Still have questions? Our team is available 24/7.
No. ColdBox delivers 95%+ inbox placement rates thanks to our built-in AI warmup engine, which gradually builds your sender reputation using a network of real inboxes. Your emails land in the Primary tab from day one. Start your free trial and see the difference in your first campaign.
Yes — unlimited accounts on every plan. Connect Gmail, Outlook, Microsoft 365, or any IMAP/SMTP provider. ColdBox automatically spreads your sending volume across inboxes to maximize deliverability and keep your domains safe. Most teams are fully connected in under 5 minutes.
Plans range from 5,000 emails/month on Starter ($30/mo) to 525,000 on Max ($319/mo). Every limit is designed to protect your domain reputation while maximizing outreach volume. Need more? Contact us for custom enterprise limits. Start free with our Trial plan to test the platform risk-free.
AI Reply Agents automatically respond to prospect replies in under 60 seconds — handling objections, answering questions, and booking meetings on your calendar via Calendly. Choose full Autopilot for hands-free operation, or Human-in-the-Loop where AI drafts replies for your approval. Teams using AI Reply Agents book 3x more meetings. Try them free today.
Yes. Native bi-directional sync with HubSpot, Salesforce, Pipedrive, and Zoho — plus Zapier for 5,000+ app connections. Leads, deals, and engagement data sync automatically. Connect Slack for instant reply notifications and Calendly for automated meeting booking. Setup takes minutes, not hours.
Absolutely. ColdBox supports unlimited team members with role-based permissions, shared campaign libraries, and team performance dashboards. Assign inboxes, control data access, and track every rep's results from one admin dashboard. Start your free trial and invite your entire sales team today.
Proven Cold Email Strategies from the Experts
Proven Results from Real Sales Teams
312% more replies. 8.2x ROI. 2.1x meetings per rep. Here's what happens when teams switch from manual outreach to ColdBox.
312%
Reply rate increase
47
Demos in first month
$280K
Pipeline generated
““We went from 3% reply rates to 18% in 6 weeks. ColdBox's warmup alone changed everything.”
Marcus T.
Head of Sales · Series A SaaS
8.2x
ROI on outreach
3 hrs/wk
Saved per rep
94%
Inbox placement
““The AI reply agents handle objections better than some of our junior reps. I'm not joking.”
Priya S.
CEO · Digital Agency
200K+
Emails per month
95%
Inbox placement
2.1x
Meetings per SDR
““Managing 40 inboxes across 8 domains used to require a full-time person. ColdBox automated all of it.”
Daniel K.
Sales Director · Fortune 500 SDR Team



