Stop Missing Positive Replies
Connect Instantly, Smartlead, and EmailBison directly to your Slack workspace. Reply to leads without leaving Slack.
Free for first 100 users - 23 spots left
Mobile ready. Hubspot & Salesforce sync coming soon.
The #1 Unibox for Cold Email Outreach
Whether you manage one campaign or hundreds, ColdStack helps you stay on top of every reply without leaving Slack.
Connect Your Sender
Link your Instantly, Smartlead, or EmailBison accounts to ColdStack in seconds. No complex setup required.
Receive Replies in Slack
All positive replies from your campaigns automatically flow into a dedicated Slack channel. Never miss a hot lead again.
Reply Instantly from Slack
Click reply directly in Slack and your response goes straight to the lead. No need to log into multiple platforms.
Close Deals 3x Faster
Respond to warm leads in minutes, not hours. Your team stays in Slack while booking more meetings than ever.
Simple, transparent pricing
Choose your plan. All plans include unlimited team members and real-time notifications.
For the first 100 users
Frequently Asked Questions
Everything you need to know about ColdStack
Ready to 3x Your Booked Meetings?
Join sales teams already managing their cold email outreach from Slack
Free for early users • No credit card required