Our Verdict
Standalone email warmup tool that warms your inboxes before you start sending cold email. Connects to your email accounts and exchanges real emails with its warmup network to build sender reputation.
What is Warmbox?
Warmbox is a cold email & deliverability tool. Standalone email warmup tool that warms your inboxes before you start sending cold email. Connects to your email accounts and exchanges real emails with its warmup network to build sender reputation.
Best for: Cold email senders who need to warm up new domains or recover damaged sender reputation
Best For
Cold email senders who need to warm up new domains or recover damaged sender reputation
Pros & Cons
- Affordable standalone warmup
- Works with any email provider
- Detailed deliverability analytics
- Only does warmup, not sending
- Smaller warmup network than Instantly's built-in
- Less useful if your cold email tool includes warmup
Key Features
- Inbox warmup
- Deliverability monitoring
- Reputation scoring
- Blacklist monitoring
- Multiple inbox support
- Analytics dashboard
Pricing
| Plan | Price |
|---|---|
| Solo | $15/mo |
| Start | $69/mo |
| Growth | $139/mo |
| Team | $269/mo |
Pricing as of 2026. Check Warmbox's website for current pricing.
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Reviewed by the B2B Sales Tools Editorial Team. Last verified 2026-04-12.
Pricing, features, and ratings are based on vendor documentation, public filings, product demos, and feedback from sales teams using these tools in production. We update reviews when vendors ship major releases or change pricing.