Hosted Sellbird is in early access with pricing to be shared before launch. Email accounts and AI plans are billed separately by their providers. Domain purchases and additional inboxes incur separate charges.
Key features
Mailbox warmup with automatic reputation building
Campaign sequences with A/B testing
Unified inbox with reply classification
Deliverability tracking and inbox placement tests
Automation workflows with conditional logic
Per-mailbox safety caps and throttling
Find companies matching your customer profile with buying signals
AI agent integration over MCP protocol
Personalized email drafting from research
Draft approval workflow by default
Email warmup and sending infrastructure
Reply collection and sorting
Agent-drafted reply responses
Support for Google Workspace and Microsoft 365
CSV export of contacts and lists
What makes it different
Fully open-source codebase under Apache 2.0, readable on GitHub
Self-hostable with one command or cloud-hosted options
Unlimited mailboxes on paid plans, no per-mailbox fees
Transparent health rules with full explanations for throttling
Built in public with public changelog and no inflated metrics
Works with the AI agent you already use—no competing AI, no additional AI costs
Human approval on by default—every email, purchase and reach requires human approval
Open-source and self-hostable version is free
Email verification works independently without running full outreach
Agents work offline after scheduling—emails send and replies collect 24/7
Warmbly
Sellbird