You write the emails. We run the sending.
A cold email platform with the domains, mailboxes, warmup, and monitoring handled for you, without the agency price tag. From $97 a month.
Who does what
You keep the parts only you can do.
You pay for a monthly sending volume. Keeping that volume healthy is on us.
Your job
- Pick who you want to reach
- Write what you want to say
- Reply to the people who are interested
Our job
- Buy and set up your domains and mailboxes
- Warm them up and keep watch on every domain
- Replace any mailbox that burns out, at no extra cost
- Keep your sending volume where your plan says it should be
- Talk strategy and messaging with you, as often as you want
Want us to do more? Add list building or reply handling on Growth and above.
Works where you work
Run your outbound from Claude or ChatGPT.
Ask for a campaign, check your replies, or pull your numbers without opening the app. Included on every plan.
- Connector for Claude, ChatGPT, and other AI tools
- API for anything you want to build
- Webhooks for replies and campaign events
Compare
Furnace next to the alternatives.
| Category | Instantly or Smartlead | Furnace | Typical agency |
|---|---|---|---|
| 12,000 emails a month | About $230 to $380, plus your time | $297 a month | $2,500+ |
| Domains and mailboxes | Bought separately, about $4 to $5 a mailbox | Included, with backups | Usually included |
| Warmup | Automated tool included | We run it | Done for you |
| Deliverability monitoring | Placement testing is a paid add-on | We watch every domain | Done for you |
| When a mailbox burns out | You replace it | We replace it, no charge | Varies |
| Leads | Their own database, usually paid extra | Sourced wherever your audience is, 3 to 5¢ each | Included in the retainer |
| Strategy help | Chat support. Calls on top plans or paid | Unlimited calls on every plan | Included |
| AI connector, API and webhooks | Yes, some on higher plans | On every plan | Depends on their tools |
| Who writes the emails | You | You, with our help | The agency |
| Free trial | 14 days | No | No |
| Commitment | Monthly | Month to month | Often a minimum term |
Instantly and Smartlead details are from their public pricing pages, September 2026.
Stay on Instantly or Smartlead if you'd rather run the technical side yourself. Pick Furnace if you'd rather hand it off.
Results
What customers have sent, and got back.
- 5
- interested replies per 1,000 emails
- 1.7%
- reply rate
- 1.5%
- bounce rate
All time, across 563,000 emails sent for customers. Your results depend on your offer and your audience.
Therapy matching platform simplifying the search for mental health professionals.
30-Day Performance
Emails Sent
30,398
Interested Prospects
1,097
Reply Rate
28
emails per positive reply
1150% better than industry
Industry: 350
Sports team management platform creating fair teams and stress-free seasons.
30-Day Performance
Emails Sent
18,182
Interested Prospects
93
Reply Rate
196
emails per positive reply
79% better than industry
Industry: 350
Real estate coaching program by Ryan Secrist helping agents grow with proven systems.
30-Day Performance
Emails Sent
5,190
Interested Prospects
43
Reply Rate
121
emails per positive reply
189% better than industry
Industry: 350
Therapy matching platform simplifying the search for mental health professionals.
30-Day Performance
Emails Sent
30,398
Interested Prospects
1,097
Reply Rate
28
emails per positive reply
1150% better than industry
Industry: 350
Sports team management platform creating fair teams and stress-free seasons.
30-Day Performance
Emails Sent
18,182
Interested Prospects
93
Reply Rate
196
emails per positive reply
79% better than industry
Industry: 350
Real estate coaching program by Ryan Secrist helping agents grow with proven systems.
30-Day Performance
Emails Sent
5,190
Interested Prospects
43
Reply Rate
121
emails per positive reply
189% better than industry
Industry: 350
Pricing
Pick a volume. Change it any time.
Starter
$97/mo
3,600 emails / mo
Reaches about 1,800 people
Growth
$297/mo
12,000 emails / mo
Reaches about 6,000 people
Scale
$497/mo
24,000 emails / mo
Reaches about 12,000 people
Enterprise
Custom
30,000+ emails / mo
For high-volume teams
Real people
Two founders on your account.
When something needs a person, you get one of us.
Kyle Nelson
Cofounder
Watches your account and takes strategy calls as often as you want them.
Porter Gardiner
Cofounder
Built the platform and answers support directly, with no limit.
Questions
What does Furnace do?
Furnace is a cold email platform that comes with the sending side handled. We set up your domains and mailboxes, warm them up, watch them, and replace any that burn out. You decide who to email and what to say.
Do I need my own domains or mailboxes?
No. Every plan includes sending domains, mailboxes, and backups. We buy them, set them up, and manage them for you.
How fast can I start?
We set up your domains and mailboxes as soon as you sign up. They warm up for about three weeks before your first send.
Will this hurt my main domain?
No. You send from separate domains we set up for you, so your main domain stays protected.
Who writes the emails?
You do, with help. Every plan includes help with your messaging and strategy calls as often as you want them.
Where do the leads come from?
Bring your own list on any plan. On Growth and above you can add list building: we source people who match your audience from whichever data providers cover them, at 3 to 5 cents each, with a verified email.
Can I use it from Claude, ChatGPT, or my CRM?
Yes. Every plan includes a connector for AI assistants like Claude and ChatGPT, an API, and webhooks. CRM sync to tools like HubSpot and Salesforce runs through OutboundSync.
Can I cancel?
Yes. Everything is month to month. If you only want to pause outreach, you can keep your domains and mailboxes warming so you can restart without the wait.
Ready to stop managing mailboxes?
Tell us who you want to reach. We'll set up the sending and show you around.
Book a call