GMass vs Inboxy: Cold Email Platform vs Email Warmup Tool Comparison
Compare GMass (cold email platform) and Inboxy (email warmup tool) side by side. See pricing, features, and integrations to decide which one, or both, your stack needs.
Compare GMass (cold email platform) and Inboxy (email warmup tool) side by side. See pricing, features, and integrations to decide which one, or both, your stack needs.
Reviewed and updated September 2, 2026
GMass vs Inboxy: Cold Email Platform vs Email Warmup Tool Comparison
Sales teams building an outbound stack often weigh GMass, a cold email platform for cold email outreach, against Inboxy, an email warmup tool for email domain warming and deliverability. 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
GMass is a cold email platform for cold email outreach; Inboxy 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 Inboxy lists primary inbox supercharger and domain score iq monitoring.
GMass offers a lower entry point at $29.95/mo compared to Inboxy at $47/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 Inboxy. 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.
Inboxy is Email warmup tool that improves deliverability by gradually increasing sending volume and boosting domain reputation. It runs warmup through a private network of headless browsers with AI-driven adjustments to sending metrics.
The two platforms take different approaches to solving the same core challenge.
Pricing Comparison
Standard
Inboxy Pro
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
Inboxy Pricing (as of September 2026)
| Plan | Price | Contacts | Emails |
|---|---|---|---|
| Inboxy Pro | $47/mo | Gmail and Office 365 Inboxes | 120 Daily Emails Per Inbox |
Source: Inboxy Pricing
Pricing Analysis
GMass is more affordable at the entry level ($29.95/mo vs $47/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.
GMass offers 4 pricing tiers compared to Inboxy's 1, giving you more granularity as you scale.
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
- Primary Inbox Supercharger
- Domain Score IQ Monitoring
- AI Powered Inbox Adjustments
- Dynamic Email Scheduling
- Live Inbox Engagement Feed
- AI Generated Emails (GPT-3)
- 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
Inboxy Key Features
- Primary Inbox Supercharger
- Domain Score IQ Monitoring
- AI Powered Inbox Adjustments
- Dynamic Email Scheduling
- Live Inbox Engagement Feed
- AI Generated Emails (GPT-3)
- IP Warm Up Service
- SMTP Warm Up Service
- Inbox Placement Test
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 Inboxy
- Primary Inbox Supercharger
- Domain Score IQ Monitoring
- AI Powered Inbox Adjustments
- Dynamic Email Scheduling
- Live Inbox Engagement Feed
- AI Generated Emails (GPT-3)
- IP Warm Up Service
- SMTP Warm Up Service
- Inbox Placement Test
Integration Ecosystem
GMass Integrations
GMass connects with: Gmail, Google Sheets, Zapier, Google Workspace.
Inboxy Integrations
Inboxy connects with: Personal Gmail, Google Workspace, Outlook/Office (SMTP), Outlook/Office (Oauth), Mailgun, GoDaddy, Inboxroad, Sendgrid, Custom SMTP.
Shared Integrations
Both tools integrate with: Google Workspace.
Integrations listed only by GMass: Gmail, Google Sheets, Zapier.
Integrations listed only by Inboxy: Personal Gmail, Outlook/Office (SMTP), Outlook/Office (Oauth), Mailgun, GoDaddy, Inboxroad, Sendgrid, 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 Inboxy
- Budget-conscious teams looking for an affordable email warmup tool
- Organizations with complex tech stacks needing broad integration support (9 integrations)
- Teams launching new email domains for outreach
- Organizations recovering from deliverability issues
Feature Comparison Summary
| Feature | GMass | Inboxy |
|---|---|---|
| Starting Price | $29.95/mo | $47/mo |
| Top Tier Price | $175/mo | $47/mo |
| Total Features Listed | 10 | 9 |
| Integrations | 4 | 9 |
| 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 Inboxy the email domain warming and deliverability side. GMass offers a more accessible entry point at $29.95/mo, while Inboxy starts at $47/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 Inboxy 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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