Guide
GMass Review: Pricing, Extension, MCP & Alternatives
GMass is a Chrome extension that turns Gmail into a mail-merge and cold email tool, sending from your own Google account. Here's a fair review of its pricing, the extension, the MCP question, how it compares with Mailchimp, and how to send at volume safely.
- [email protected]Customers only
- [email protected]Pre-warmed · 30/day
- [email protected]Pre-warmed · 30/day
- [email protected]Pre-warmed · 30/day
90 cold emails a day · main domain untouched
Overview
What is GMass and how does it work?
GMass adds its own buttons to Gmail. You connect a Google Sheet, where each row becomes a recipient and each column a merge field, write the email in Gmail's compose window and send it as a campaign.
- free trial
- 7 days
- emails per rolling 24 hours on the trial
- 50
- per month for Standard, billed yearly
- $20.75
- messages a day Google allows a Workspace user
- 2,000
On top of mail merge it does auto follow-ups, open and click tracking, a Spam Solver, free email verification, inbox rotation across several Gmail accounts (MultiSend), and an option to send larger campaigns through an SMTP service. Developers get an API, webhooks, Zapier and an SMTP relay.
Pricing
GMass pricing
From GMass's pricing page and its January 2026 price update, as of October 2026. Every plan advertises unlimited emails, but Gmail's own limits still apply.
| Plan | Monthly | Yearly | Adds |
|---|---|---|---|
| Standard | $29.95/mo | $249/yr ($20.75/mo) | Mail merge, tracking, Spam Solver, free verification |
| Premium | $39.95/mo | $349/yr ($29.08/mo) | Auto follow-ups, API and Zapier, A/B testing, triggered emails |
| Professional | $59.95/mo | $599/yr ($49.92/mo) | MultiSend inbox rotation, high-priority support |
| Team (5 users) | $175/mo | $1,750/yr | Professional features for every user |
Extension & MCP
How to set up the GMass extension
- On a desktop, install the GMass extension from the Chrome Web Store and click Add extension.
- Back in Gmail, click Sign up with Google and allow the permissions GMass needs to send from your account.
- Click the Google Sheets button GMass adds next to the Gmail search bar, pick your sheet and connect it.
- Write the email and type a curly brace to insert merge fields like {FirstName}; add a fallback after a pipe.
- Open settings with the arrow next to the GMass button, then click GMass to send or schedule.
GMass MCP
As of October 2026, gmass.co doesn't list an official MCP server. Third-party bridges such as Zapier MCP and viaSocket expose GMass API actions, for example sending a transactional email, adding an address to your unsubscribe list or removing it from a campaign, to AI assistants. They're not built by GMass, so review the account access you grant.
Data is half the job; deliverability is the other half
Compare
GMass vs Mailchimp, pros, cons and alternatives
| GMass | Mailchimp | |
|---|---|---|
| Sends from | Your Gmail or Workspace account | Mailchimp's servers |
| Built for | Personal-looking email, mail merge, outreach | Newsletters to opted-in subscribers |
| Cold outreach | A listed use case | Not allowed: no purchased or third-party lists |
| Entry price | $29.95/mo, unlimited contacts | Free to 250 contacts; Standard from $20/mo |
| Strengths | Trade-offs |
|---|---|
| Works inside Gmail; emails look hand-written | Bound by Gmail's daily limits |
| Google Sheets as a live list | Follow-ups need Premium or above |
| Flat pricing, unlimited contacts | Inbox rotation needs Professional or a team plan |
| API, webhooks and SMTP relay | No official MCP server yet |
| Tool | Entry price | Sends from | Best for |
|---|---|---|---|
| GMass | $29.95/mo | Your Gmail or Workspace account | Mail merge and light outreach |
| Mailchimp | Free; Standard from $20/mo | Mailchimp's servers | Opt-in newsletters |
| Instantly | Growth from $47/mo | Mailboxes you connect | Cold email across many mailboxes |
| Hunter.io | Free; Starter $49/mo | Connected email accounts | Finding emails plus simple sequences |
| Apollo.io | Free; Basic $49/seat/mo yearly | Connected mailboxes | Data plus sequences |
Next step
Found your leads? Send from mailboxes that land
Google's limit is a ceiling, not a target. Cold email stays out of spam at a fraction of it, spread across dedicated mailboxes.
Daily sending limits vs a safe cold email pace
Google's published limits (Gmail help, Workspace admin help), GMass's trial cap, and the per-mailbox pace Jetmail plans for.
| Google Workspace | 2,000 |
|---|---|
| Personal Gmail | 500 |
| Workspace trial | 500 |
| GMass trial | 50 |
| Cold email pace | 30 |
Step 1
Find
Build the list in a Google Sheet.
Step 2
Verify
Remove invalid and risky addresses first.
Step 3
Pre-warmed mailboxes
Workspace mailboxes on separate domains.
Step 4
Send
About 30 a day each, rotated.
Step 5
Reply
Plain text, one question.
Jetmail's Google mailboxes are Google Workspace accounts on dedicated cold email domains, so you can sign in to them in Gmail and run GMass as usual, or connect them to 50+ sequencers. Compare sending tools in best cold email software.
Sources: gmass.co/pricing · GMass: Jan 2026 price changes · GMass pricing FAQ · GMass quickstart guide · Google: Gmail sending limits · Google Workspace sending limits · Zapier MCP: GMass · viaSocket: GMass MCP · Mailchimp pricing · Mailchimp acceptable use · instantly.ai/pricing
GMass is a trademark of its owner. Jetmail isn't affiliated with or endorsed by it. Other product names belong to their respective owners.
Get a free outbound setup plan
Tell us where to send it. We'll reply with mailbox, domain and DNS recommendations for your sending volume — or start right away and have mailboxes live in minutes.
Where should we send it?
Or see pricing →Frequently asked questions
What is GMass?
GMass is a Chrome extension that adds mail-merge and campaign buttons to Gmail. It sends personalized campaigns, follow-ups and tracked emails from your own Gmail or Google Workspace account, usually with a Google Sheet as the list.
How much does GMass cost?
As of October 2026: Standard $29.95 a month or $249 a year, Premium $39.95 or $349, and Professional $59.95 or $599. Team plans start at $175 a month for 5 users. The free trial lasts 7 days and is capped at 50 emails per rolling 24 hours.
Does GMass get around Gmail's sending limits?
Not by itself. GMass says paying for it doesn't raise Gmail's own limits: about 500 emails a day for a personal Gmail account and 2,000 messages a day for a Google Workspace user. For bigger sends GMass can route mail through an SMTP service you connect. For cold email, more mailboxes at a lower volume each is the safer fix.
Is there a GMass MCP server?
As of October 2026, gmass.co doesn't list an official MCP server. GMass offers an API, webhooks, Zapier, a Sheets API and SMTP relay, and third parties such as Zapier MCP and viaSocket expose GMass actions (for example sending a transactional email or adding an unsubscribe) to AI assistants.
GMass vs Mailchimp: which should I use?
Use Mailchimp for designed newsletters to people who opted in; its acceptable use policy bans purchased, rented and third-party lists. Use GMass for personal-looking emails sent from Gmail, including small-volume cold outreach.
Is GMass good for cold email?
For modest volumes from Gmail, yes: it's simple, cheap and plain-text friendly. At scale you need several dedicated mailboxes on separate domains, which GMass can rotate with MultiSend on Professional and team plans, or a dedicated sequencer.