GMass vs Mailwarm: Cold Email Platform vs Email Warmup Tool Comparison
Compare GMass (cold email platform) and Mailwarm (email warmup tool) side by side. See pricing, features, and integrations to decide which one, or both, your stack needs.
GMass and Mailwarm serve different parts of the email workflow and are not direct substitutes. GMass is a Gmail-based cold email platform starting at $29.95/mo for unlimited emails, contacts, and campaigns. Mailwarm is an email warmup tool starting at $79/mo that builds sender reputation and inbox placement. Many teams use both together.
Key takeaways
- GMass entry pricing starts at $29.95/mo for the Standard plan with unlimited contacts and emails, subject to Gmail limits.
- Mailwarm entry pricing starts at $79/mo for the Starter plan, which covers one mailbox or SMTP to warm and up to 50 warmup emails per day.
- GMass integrates with Gmail, Google Sheets, Zapier, and Google Workspace, while Mailwarm integrates with Gmail, Google Workspace, Outlook, Microsoft 365, Yahoo, and Custom SMTP.
- Mailwarm includes a deliverability expert on every plan and generates engagement signals such as marking as non-spam, opening, marking as important, and replying.
- GMass lists ten features including Spam Solver, inbox rotation, and API and Zapier access, while Mailwarm lists nine features including SPF, DKIM, and DMARC validation and blacklist detection.
Reviewed and updated September 2, 2026
GMass vs Mailwarm: Cold Email Platform vs Email Warmup Tool Comparison
GMass is a cold email platform; Mailwarm is an email warmup tool. Whether you need one, the other, or both depends on which part of the workflow you are buying for: cold email outreach on one side, email domain warming and deliverability on the other. This guide lays out what each vendor publishes.
The Quick Answer
GMass is a cold email platform for cold email outreach; Mailwarm is an email warmup tool for email domain warming and deliverability. By each vendor's own wording, GMass lists works inside gmail and unlimited emails, contacts, and campaigns, and Mailwarm lists b2b & b2c warm up and spam score monitoring.
GMass offers a lower entry point at $29.95/mo compared to Mailwarm at $79/mo.
If your priority is sending campaigns that land in the inbox and generate replies, GMass is the one built for it; for building sender reputation and improving inbox placement, that is Mailwarm. Many teams run one of each.
Understanding the Core Difference
GMass is Gmail-based mass email and mail merge platform with unlimited emails, campaigns, and contacts directly inside Gmail.
Mailwarm is Email warmup and deliverability platform that generates engagement across a network of aged real inboxes and includes a deliverability expert on every plan. Each interaction produces several positive signals, such as marking as non-spam, opening, marking as important and replying.
The two platforms take different approaches to solving the same core challenge.
Pricing Comparison
Standard
Starter
GMass Pricing (as of September 2026)
| Plan | Price | Contacts | Emails |
|---|---|---|---|
| Standard | $29.95/mo | Unlimited | Unlimited (Gmail limits apply) |
| Premium | $39.95/mo | Unlimited | Unlimited (Gmail limits apply) |
| Professional | $59.95/mo | Unlimited | Unlimited (Gmail limits apply) |
| Teams (5 users) | $175/mo | Unlimited | Unlimited (Gmail limits apply) |
Source: GMass Pricing
Mailwarm Pricing (as of September 2026)
| Plan | Price | Contacts | Emails |
|---|---|---|---|
| Starter | $79/mo | 1 mailbox/SMTP to warm; 1 user | Up to 50 warmup emails/day |
| Growth | $189/mo | 3 mailboxes/SMTPs to warm; 2 users | Up to 200 warmup emails/day |
| Scale | $549/mo | 10 mailboxes/SMTPs to warm; 5 users | Up to 500 warmup emails/day |
| Tailored Plan | Contact Sales | unlimited mailboxes, users | unlimited warmup emails, and replies |
Source: Mailwarm Pricing
Pricing Analysis
GMass is more affordable at the entry level ($29.95/mo vs $79/mo). For teams with tight budgets or those just getting started with cold email outreach and email domain warming and deliverability, this price difference matters.
Features Breakdown
- Works inside Gmail
- Unlimited emails, contacts, and campaigns
- Mail merge personalization
- Free email verification
- Automated follow-up sequences
- A/B testing
- and 4 more listed below
- B2B & B2C warm up
- Spam score monitoring
- Provider-Level warmup
- Warmup your email content
- Authentication fix tools
- No IMAP access required
- and 3 more listed below
GMass Key Features
- Works inside Gmail
- Unlimited emails, contacts, and campaigns
- Mail merge personalization
- Free email verification
- Automated follow-up sequences
- A/B testing
- Spam Solver deliverability tool
- Custom tracking links
- Inbox rotation
- API and Zapier access
Mailwarm Key Features
- B2B & B2C warm up
- Spam score monitoring
- Provider-Level warmup
- Warmup your email content
- Authentication fix tools
- No IMAP access required
- Progressive volume ramp-up to avoid spam filters
- SPF, DKIM, and DMARC validation
- Blacklist detection across major databases
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 GMass
- Works inside Gmail
- Unlimited emails, contacts, and campaigns
- Mail merge personalization
- Free email verification
- Automated follow-up sequences
- A/B testing
- Spam Solver deliverability tool
- Custom tracking links
- Inbox rotation
- API and Zapier access
Listed only by Mailwarm
- B2B & B2C warm up
- Spam score monitoring
- Provider-Level warmup
- Warmup your email content
- Authentication fix tools
- No IMAP access required
- Progressive volume ramp-up to avoid spam filters
- SPF, DKIM, and DMARC validation
- Blacklist detection across major databases
Integration Ecosystem
GMass Integrations
GMass connects with: Gmail, Google Sheets, Zapier, Google Workspace.
Mailwarm Integrations
Mailwarm connects with: Gmail, Google Workspace, Outlook, Microsoft 365, Yahoo, Custom SMTP.
Shared Integrations
Both tools integrate with: Gmail, Google Workspace.
Integrations listed only by GMass: Google Sheets, Zapier.
Integrations listed only by Mailwarm: Outlook, Microsoft 365, Yahoo, Custom SMTP.
Use Case Recommendations
Best Fit for GMass
- Budget-conscious teams looking for an affordable cold email platform
- Teams that need a wide feature set (10 capabilities listed)
- Sales teams running high-volume outbound email campaigns
- Agencies managing multiple client outreach programs
Best Fit for Mailwarm
- Organizations with complex tech stacks needing broad integration support (6 integrations)
- Enterprise buyers who prefer custom pricing and dedicated support
- Teams launching new email domains for outreach
- Organizations recovering from deliverability issues
Feature Comparison Summary
| Feature | GMass | Mailwarm |
|---|---|---|
| Starting Price | $29.95/mo | $79/mo |
| Top Tier Price | $175/mo | Contact Sales |
| Total Features Listed | 10 | 9 |
| Integrations | 4 | 6 |
| Founded | 2015 | N/A |
Getting Started Checklist
- Define your cold email outreach and email domain warming and deliverability requirements and monthly budget
- Estimate your expected email sending volume and warmup email 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
GMass serves the cold email outreach side of an outbound stack and Mailwarm the email domain warming and deliverability side. GMass offers a more accessible entry point at $29.95/mo, while Mailwarm starts at $79/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 GMass and Mailwarm for current information.
Frequently asked questions.
Frequently asked questions- What is the difference between GMass and Mailwarm?
- GMass is a cold email platform built for sending outreach campaigns from Gmail, with unlimited emails, contacts, and campaigns. Mailwarm is an email warmup tool that builds sender reputation and improves inbox placement by generating engagement across a network of aged real inboxes. They address different stages of the email workflow.
- Which is cheaper, GMass or Mailwarm?
- GMass is cheaper at the entry level, starting at $29.95/mo compared to Mailwarm's $79/mo Starter plan. For budget-conscious teams or those just starting with cold email outreach and deliverability, this price gap is a meaningful factor in choosing where to start.
- Do I need both GMass and Mailwarm?
- Many teams use both, since GMass handles sending campaigns that land in the inbox and generate replies, while Mailwarm focuses on building sender reputation and improving deliverability. They are not competing tools but cover different parts of the same email workflow.
- What integrations does GMass support compared to Mailwarm?
- GMass connects with Gmail, Google Sheets, Zapier, and Google Workspace. Mailwarm connects with Gmail, Google Workspace, Outlook, Microsoft 365, Yahoo, and Custom SMTP. Both tools share Gmail and Google Workspace integrations, but Mailwarm supports a broader range of email providers.
- What features does Mailwarm offer that GMass does not?
- Mailwarm lists features such as B2B and B2C warmup, spam score monitoring, provider-level warmup, authentication fix tools, no IMAP access required, progressive volume ramp-up to avoid spam filters, SPF, DKIM, and DMARC validation, and blacklist detection across major databases, none of which appear on GMass's published feature list.
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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