Warmforge
Warm up inboxes, land in primary.
What is Warmforge
Warmforge automates the email warm-up process by sending and replying to AI-written messages that mimic human behavior, signaling trustworthiness to email service providers over time. It's built for SDRs, BDRs, and RevOps teams at SMBs and mid-market companies running cold outreach at scale across multiple domains and mailboxes. The standout capability is its Heat Score™ system, which gives each mailbox a trackable reputation score alongside always-on warm-up and automated spam recovery — so you're not just warming once, you're maintaining deliverability continuously. It integrates with Google Workspace and Microsoft 365 and fits neatly into the broader Salesforge/Mailforge stack. That said, if you're not already running cold email volume, the per-slot pricing model adds up quickly and the tool has limited utility outside of deliverability — it won't help you write sequences or manage contacts.
Key features
warmup, spam tests, and sender reputation
AI-drafted personalised copy
Vanderbuild take
For SDR and RevOps teams whose cold email volume makes deliverability a first-order problem, Warmforge is a focused, no-frills tool that does one thing — keeps your mailboxes out of spam — and does it with enough automation to run across dozens of domains without manual babysitting. On the agentic readiness front, the API exists but it's limited; you can pull deliverability metrics into a broader workflow, but don't expect to build a serious agentic orchestration layer on top of it without hitting walls. At $10 per slot per month, it's affordable for small teams, though costs scale linearly as you add mailboxes and the placement test plans jump meaningfully at higher tiers. The honest limitation: Warmforge is purely a deliverability layer — it has no sequencing, no contact management, and no reporting depth beyond mailbox health, so you'll need to pair it with a sending tool to get anything close to a full outbound stack.
Agentic stack profile
MCP serverNoNo MCP. Use the REST API or SDK to integrate with agents.
If you want to use this in an agentic workflow, wrap the REST API in a custom MCP server.
APIRESTProgrammatic access available.
REST API — straightforward to call from any agent or workflow tool. Rate limits and auth vary by plan.
Agentic readinessLimitedUsable but with caveats — rate limits, brittle endpoints.
API exists but is rate-limited, brittle, undocumented, or hidden behind enterprise plans. Use with caution in production agent workflows.
Stack roleDeliverabilityWhere this tool slots into an agentic pipeline.
Plays the role of Deliverability in an agentic pipeline. Use it to keep email sending reputation healthy — warmup, spam tests.
Warmforge alternatives
Tools that solve a similar problem — compared at a glance.
- Pricing
- Client-based
- Budget
- $$
- Best for
- SDR / BDR, RevOps
- Readiness
- Limited
- MCP
- No
- API
- REST
- Pricing
- Usage-based
- Budget
- $
- Best for
- Founder, GTM Engineer
- Readiness
- Capable
- MCP
- No
- API
- REST
- Pricing
- Custom
- Budget
- $$$$
- Best for
- SDR / BDR, RevOps
- Readiness
- Capable
- API
- REST
Frequently asked questions
Does Warmforge have an MCP server?
No — Warmforge doesn't expose an MCP endpoint. You can wrap its REST API in your own agent tooling instead.
Does Warmforge have a public API?
Yes — Warmforge ships a REST API. Note the API is rate-limited or enterprise-gated, so plan integrations accordingly.
How much does Warmforge cost?
Warmforge: pricing is client-based, expect mid tier ($$) spend. Full pricing page: https://www.warmforge.ai/pricing.
Who is Warmforge best for?
Warmforge is built for SDR / BDR, RevOps. Fits SMB (1-50), Mid-market (50-500)-sized teams.
How well does Warmforge fit an agentic sales stack?
Tier: Limited. An API exists but it's rate-limited, brittle, or enterprise-gated. Plan integrations carefully.