MailHeat vs Reply.io: Email Warmup Tool vs Cold Email Platform Comparison
Compare MailHeat (email warmup tool) and Reply.io (cold email platform) side by side. See pricing, features, and integrations to decide which one, or both, your stack needs.
Compare MailHeat (email warmup tool) and Reply.io (cold email platform) side by side. See pricing, features, and integrations to decide which one, or both, your stack needs.
Reviewed and updated September 4, 2026
MailHeat vs Reply.io: Email Warmup Tool vs Cold Email Platform Comparison
Sales teams building an outbound stack often weigh MailHeat, an email warmup tool for email domain warming and deliverability, against Reply.io, a cold email platform for cold email outreach. They cover different parts of the workflow, so this comparison covers what each one does, what each one costs, and where they overlap.
The Quick Answer
MailHeat is an email warmup tool for email domain warming and deliverability; Reply.io is a cold email platform for cold email outreach. By each vendor's own wording, MailHeat lists secure smtp connection and health & activity dashboard, and Reply.io lists unlimited email warmup and 1 billion b2b contacts database.
Reply.io offers a lower entry point at $59/mo compared to MailHeat at $69.99/mo.
If your priority is building sender reputation and improving inbox placement, MailHeat is the one built for it; for sending campaigns that land in the inbox and generate replies, that is Reply.io. Many teams run one of each.
Understanding the Core Difference
MailHeat is Inbox warmup and deliverability platform that simulates the positive engagement mailbox providers reward across a warmup pool, with gradual pacing, a per-inbox health dashboard and deliverability expert consulting on the higher tiers.
Reply.io is AI-powered sales engagement platform with 1B+ B2B contacts, multichannel sequences, and AI SDR capabilities.
The two platforms take different approaches to solving the same core challenge.
Pricing Comparison
Starter
Email Volume
MailHeat Pricing (as of September 2026)
| Plan | Price | Contacts | Emails |
|---|---|---|---|
| Starter | $69.99/mo | 1 account to warm (1 SMTP); 1 user | Up to 50 emails/day |
| Growth | $159.99/mo | Up to 3 accounts to warm (3 SMTPs); 2 users | Up to 200 emails/day per inbox |
| Scale | $479.99/mo | Up to 10 accounts to warm (10 SMTPs); 5 users | Up to 500 emails/day per inbox |
| Tailored Plan | Contact Sales | Unlimited accounts & SMTPs; unlimited users | Unlimited emails/day |
Source: MailHeat Pricing
Reply.io Pricing (as of September 2026)
| Plan | Price | Contacts | Emails |
|---|---|---|---|
| Email Volume | $59/mo | 1,000 active contacts | Unlimited |
| Multichannel | $99/mo | Unlimited active contacts | Unlimited emails; 10 mailboxes |
| Agency Core | $210/mo | Unlimited clients & users | Unlimited mailboxes |
| AI SDR Starter | $800/mo | 1,000 active contacts | Unlimited mailboxes & warm-ups |
Source: Reply.io Pricing
Pricing Analysis
Reply.io offers the lower entry point ($59/mo vs $69.99/mo). Teams watching their budget will appreciate the savings, especially when starting out.
Features Breakdown
- Secure SMTP connection
- Health & activity dashboard
- Gradual warmup pacing
- Email & chat support
- Deliverability expert consulting
- Free Deliverability Audit
- and 2 more listed below
- Unlimited email warmup
- 1 billion B2B contacts database
- Anti-spam & deliverability suite
- LinkedIn automation (add-on)
- SMS and calls (add-on)
- AI personalization
- and 3 more listed below
MailHeat Key Features
- Secure SMTP connection
- Health & activity dashboard
- Gradual warmup pacing
- Email & chat support
- Deliverability expert consulting
- Free Deliverability Audit
- Success Manager
- Free tools
Reply.io Key Features
- Unlimited email warmup
- 1 billion B2B contacts database
- Anti-spam & deliverability suite
- LinkedIn automation (add-on)
- SMS and calls (add-on)
- AI personalization
- AI SDR capabilities
- Multi-workspace for agencies
- 14-day free trial
The two lists below are a diff of each vendor's own feature list by exact wording, so a capability both tools offer can appear on either side under a different name.
Listed only by MailHeat
- Secure SMTP connection
- Health & activity dashboard
- Gradual warmup pacing
- Email & chat support
- Deliverability expert consulting
- Free Deliverability Audit
- Success Manager
- Free tools
Listed only by Reply.io
- Unlimited email warmup
- 1 billion B2B contacts database
- Anti-spam & deliverability suite
- LinkedIn automation (add-on)
- SMS and calls (add-on)
- AI personalization
- AI SDR capabilities
- Multi-workspace for agencies
- 14-day free trial
Integration Ecosystem
MailHeat Integrations
MailHeat connects with: SMTP, Gmail, Google Workspace, Microsoft 365, Outlook.
Reply.io Integrations
Reply.io connects with: HubSpot, Salesforce, Pipedrive, Copper CRM, Zendesk Sell, Close, Zapier, Make, n8n.
Integrations listed only by MailHeat: SMTP, Gmail, Google Workspace, Microsoft 365, Outlook.
Integrations listed only by Reply.io: HubSpot, Salesforce, Pipedrive, Copper CRM, Zendesk Sell, Close, Zapier, Make, n8n.
Use Case Recommendations
Best Fit for MailHeat
- Enterprise buyers who prefer custom pricing and dedicated support
- Teams launching new email domains for outreach
- Organizations recovering from deliverability issues
- Agencies managing warmup across multiple client domains
Best Fit for Reply.io
- Teams that need a wide feature set (9 capabilities listed)
- Organizations with complex tech stacks needing broad integration support (9 integrations)
- Sales teams running high-volume outbound email campaigns
- Agencies managing multiple client outreach programs
Feature Comparison Summary
| Feature | MailHeat | Reply.io |
|---|---|---|
| Starting Price | $69.99/mo | $59/mo |
| Top Tier Price | Contact Sales | $800/mo |
| Total Features Listed | 8 | 9 |
| Integrations | 5 | 9 |
Getting Started Checklist
- Define your email domain warming and deliverability and cold email outreach requirements and monthly budget
- Estimate your expected warmup email volume and email sending volume to find the right tier
- List the integrations your team currently relies on
- Sign up for free trials or demos of both platforms
- Run a small test with each tool before making a commitment
- Evaluate the onboarding experience and support quality
Final Thoughts
MailHeat serves the email domain warming and deliverability side of an outbound stack and Reply.io the cold email outreach side. Reply.io offers a more accessible entry point at $59/mo, while MailHeat starts at $69.99/mo. Your decision should weigh pricing against the specific features that matter most for your workflow.
Start with a trial of each to see which platform fits your team's daily process. The best tool is the one your team actually uses consistently.
Pricing and features verified as of September 2026. Visit MailHeat and Reply.io for current information.
About the author.
Tim Carden is CMO / CTO at RevenueFlow, which builds and operates outbound revenue engines for B2B companies. Studied at McGill University.
Tim Carden · CMO / CTO
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