GMass

Name: GMass
Brand: GMass
Price: 29.95249 USD

Cold email that never leaves the Gmail compose window

GMass is a Gmail mail-merge and cold email tool that runs as a Chrome extension inside Gmail, letting you send personalized mass email from your own Google account using a Google Sheet or a Gmail search as the list, with automated follow-up sequences, free list verification, custom tracking domains, and an inbox-rotation feature (MultiSend) that spreads a campaign across several connected Gmail accounts.

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Overview

GMass is the oldest and most stubbornly focused product in this category. It is not a web app with a Gmail integration; it is a Chrome extension that puts a second send button in the Gmail compose window. Your campaign is a Gmail draft, your list is a Google Sheet or the results of a Gmail search, your sent mail lives in your Sent folder, and your replies arrive in your normal inbox. That design means there is almost nothing to learn if you already use Gmail, and it means every message physically originates from a real Google mailbox rather than a relay, which is the single most important deliverability variable in cold outbound.

The tradeoff is that GMass inherits Gmail's ceiling. A consumer Gmail account is capped around 500 recipients per day and a Google Workspace account around 2,000, and GMass cannot conjure volume that Google will not permit. What it can do is spread a campaign across multiple connected accounts using MultiSend, its inbox-rotation feature on the Professional and Team plans, where only the primary account needs a paid subscription and the additional accounts connect over OAuth. For a small business running a few thousand sends a month across three or four mailboxes, that is a genuinely cheap architecture.

The company is a bootstrapped outlier. Founder Ajay Goel had already built and run JangoMail, an email service provider, before starting GMass in 2015 on a reported ten thousand dollars of his own money. Public revenue trackers put GMass around 8.6 million dollars of annual revenue in 2024 with roughly a dozen employees and hundreds of thousands of users, which is an extraordinary ratio and explains the product's unhurried, feature-dense, slightly unfashionable character. There is no venture pressure to become a platform.

One important honesty note: GMass shut down its email warm-up feature in 2023, stating publicly that Google asked it and other vendors to stop offering warm-up. GMass now recommends organic ramp-up, meaning you send small volumes to engaged recipients and let reputation build naturally. If your outbound plan assumes a bundled warm-up network, GMass is not that tool and you will be buying warm-up separately or choosing a different platform.

Best for

Solo founders, consultants, recruiters, and small teams that already live in Gmail and want a cheap, deeply capable mail-merge and cold email tool that sends from their real mailboxes, at volumes of a few hundred to a few thousand emails a day across a handful of accounts.

Not the right fit for

Anyone running a fifty-mailbox outbound machine; MultiSend rotation works, but Gmail's per-account caps and the extension-first workflow make GMass the wrong shape at that scale, and Instantly or Smartlead exist precisely for it.
Buyers who expect bundled warm-up; GMass discontinued warm-up in 2023 and will tell you to ramp organically, so you are buying MailReach, Warmy, or an equivalent separately.
Microsoft 365 shops; GMass is a Gmail product, and if your company runs on Outlook there is nothing here for you.
Teams that need a unified team inbox, deal stages, and CRM-grade reply management; GMass hands replies back to Gmail and expects you to work them there.
Anyone who wants a multichannel sequence with LinkedIn or calling steps; GMass is email only and has no ambition to be otherwise.

How it works

1
You install the Chrome extension and authorize it against your Gmail or Google Workspace account. GMass adds a red send button, a settings arrow, and a set of buttons to the Gmail toolbar. There is no separate dashboard to live in, though a web-based campaign report and settings area exist.
2
You build a list either by connecting a Google Sheet (each column becomes a merge field) or by running a Gmail search and letting GMass build the recipient list from everyone in the matching threads, which is the feature that made it popular with people who wanted to email everyone they had ever corresponded with. Lists are verified free before send, and GMass flags rows with missing personalization data rather than sending a blank greeting.
3
You write the message as an ordinary Gmail draft with merge tags, optional conditional content, and A/B test variations. Auto follow-ups are configured as part of the campaign: send stage two after four days unless the recipient replies, and so on. Sends are then paced and distributed, respecting per-account daily caps, and on Professional the MultiSend feature splits the campaign evenly across every connected account.
4
Replies and bounces are auto-categorized into labels so your inbox does not drown, and a companion tool called The Reply Project gives you a fast triage view across accounts. Campaign reports show opens, clicks, replies, and bounces, with sharable links. A REST API, webhooks, and Zapier cover programmatic and transactional sending for people who want GMass as a backend rather than a UI.

Feature breakdown

26 features in 5 modules

Sending from inside Gmail

The architecture that makes GMass different from every web-app competitor.

Chrome extension in the compose window: Campaigns are ordinary Gmail drafts sent with a second red button. There is no separate app to learn, and sent mail lands in your Sent folder like normal correspondence.
Real mailbox sending, not an SMTP relay: Mail leaves through Google's own infrastructure from your authenticated account, so you inherit Google's sending reputation rather than a shared relay's. This is the deliverability argument for the whole product.
MultiSend inbox rotation: On Professional and Team plans, a campaign is split evenly across every connected account (a thousand recipients across ten accounts becomes a hundred each). Only the primary account needs a paid seat; the rest connect over OAuth.
Bounce-aware rerouting: If an account starts bouncing mid-campaign, MultiSend reroutes remaining volume to the other connected accounts instead of continuing to burn the failing one.
Follow-ups from the original sender: Even with rotation on, follow-up stages come from whichever account sent the first message, so the thread stays coherent to the recipient.
Send scheduling and pacing: Campaigns can be scheduled, throttled, and spread over time rather than fired in one burst, which matters because Gmail's own throttling punishes spikes.

List building and personalization

Where GMass has more depth than its price suggests.

Google Sheets as the list source: Connect a Sheet and every column becomes a merge field. Editing the Sheet updates the campaign, which is a far friendlier loop than re-uploading CSVs.
Build a list from a Gmail search: Run any Gmail search and GMass extracts every address in the matching threads into a campaign list. Nothing else in this category does this, and it is the single most-cited reason people install it.
Free built-in email verification: Lists are verified before send at no extra charge, which is unusual; most competitors sell verification credits separately or push you to ZeroBounce or NeverBounce.
Conditional content and fallbacks: Blocks of copy can be shown or hidden per recipient, and GMass warns you about rows with missing merge data instead of quietly sending a broken greeting.
A/B testing on subject and body: Split campaigns across variations and read the winner in the campaign report; available on all paid tiers rather than gated to the top plan.
Unlimited contacts and campaigns: Plans are priced per user, not per contact or per email, so list growth does not change the bill. The only ceiling is what Google will let your accounts send.

Deliverability tooling

Practical, occasionally opinionated, and missing one obvious thing.

Custom tracking domain with SSL: Open and click tracking runs through your own domain with a valid certificate, keeping your links off shared tracking infrastructure that spam filters already distrust.
Spam Solver: Sends a test, checks placement, and gives AI-generated suggestions for what to change to reach the inbox. It is a placement test with an opinion attached rather than a black box score.
No bundled warm-up: GMass discontinued warm-up in 2023 after Google asked vendors to stop, and now recommends organic ramp-up through low-volume engaged sending. Treat this as a required separate purchase if your plan depends on it.
Automatic bounce handling: Bounces are detected, labeled, and excluded from follow-up stages rather than being retried into a wall.
Auto reply detection and labeling: Replies are recognized, follow-ups stop for that recipient, and responses are filed under GMass labels so your primary inbox stays usable.
Link checker: Pre-send validation of every URL in the message, which catches the broken-tracking-link failure that silently kills campaigns.

Reply management and reporting

Gmail-native rather than a separate unified inbox.

The Reply Project: A companion fast-triage interface for working through replies across connected accounts quickly, which is GMass's answer to the unified inbox that platform competitors build in.
Campaign reports: Opens, clicks, replies, bounces, and unsubscribes per campaign and per stage, with sharable report links for clients.
Automatic unsubscribe handling: GMass inserts an unsubscribe link, processes opt-outs automatically, and suppresses those addresses from future campaigns, which is the CAN-SPAM baseline you cannot skip.
Label-based organization: Replies, bounces, and campaign mail are foldered with Gmail labels rather than a proprietary datastore, so nothing is trapped if you leave.

Automation and developer surface

More API than a Gmail extension has any business having.

REST API: Create and send campaigns programmatically, manage lists, and pull stats. Included on paid plans rather than reserved for an enterprise tier.
Transactional and triggered email: Fire individual personalized messages from your Gmail account via API or webhook, which small teams use as a cheap transactional path that sends from a real human mailbox.
Zapier integration: Connects list building and campaign triggers to whatever CRM or form tool you already run.
Team plans with shared assets: Team tiers from five to a hundred users add collaboration and centralized billing while keeping each person sending from their own mailbox.

Use cases

4 documented

Solo consultant re-engaging an old network

Six years of Gmail history contains hundreds of people who once mattered, but there is no CRM and no list anywhere.

A Gmail search builds the recipient list directly from past threads, GMass verifies it free, and a three-stage sequence goes out from the consultant's real address at a few dozen a day.

Two-person agency running client outbound

They need a few thousand sends a month across four mailboxes without paying platform pricing or standing up cold-email infrastructure.

One Professional seat plus three OAuth-connected accounts under MultiSend covers the volume, custom tracking domains keep links clean, and campaign report links get shared straight to clients.

Recruiter sourcing candidates

Personalized outreach to a spreadsheet of two hundred engineers, where a message that looks like a marketing blast gets ignored instantly.

A Google Sheet drives merge fields, conditional blocks vary the pitch by seniority, and the mail arrives from a real person's Gmail with replies landing in the normal inbox.

Developer wanting personalized transactional mail from a human address

Onboarding emails from a no-reply relay get ignored, but wiring a full ESP for a handful of daily messages is overkill.

The GMass API fires triggered messages through the founder's own Gmail account, so they look like personal notes and inherit the account's reputation.

Pricing

from $29.95 per month (Standard), or $249 per year

Per-user subscription with three individual tiers and banded team plans; unlimited contacts and unlimited campaigns on every paid tier, with volume capped by Google's own per-account sending limits rather than by GMass.

Plan	Price	Includes
Standard	$29.95 per month (or $249 per year, about $20 per month)	Mail merge from Google Sheets and Gmail search Automatic follow-up sequences Free email verification Unlimited contacts and campaigns Campaign reports and label-based reply handling Enough for one person sending from one mailbox, which is most GMass users.
Premium	$39.95 per month (or $349 per year, about $29 per month)	Everything in Standard A/B testing Custom tracking links with SSL Triggered and transactional email API access and Zapier The tier where custom tracking domains arrive, which matters more for deliverability than most of the features above it.
Professional	$59.95 per month (or $599 per year, about $49 per month)	Everything in Premium MultiSend inbox rotation across multiple connected accounts Spam Solver placement testing and suggestions Priority email support Connected accounts do not need their own subscription The only tier that makes sense if you run more than one sending mailbox, and the reason cold emailers pick GMass at all.
Team (5 users, Premium)	$175 per month (or $1,750 per year)	Five Premium seats with centralized billing Team collaboration features Each user still sends from their own mailbox Bands published at 5, 10, 25, 50, and 100 users 10 users at $295 per month, 25 at $604, 50 at $1,125, 100 at $1,833

Billing notes

Annual billing is roughly a third cheaper than monthly on every individual tier: $249, $349, and $599 per year against $29.95, $39.95, and $59.95 per month.
Pricing is per user and never per contact or per email, so a list of two thousand and a list of two hundred thousand cost the same. Your real constraint is Google's daily cap per mailbox.
Under MultiSend, only the primary account carries a paid subscription; additional connected sending accounts are free, which makes the $59.95 Professional tier the cheapest legitimate multi-mailbox setup in this category.
Email verification is included at no extra cost, which quietly removes a line item most competitors bill separately.
There is no warm-up service to buy from GMass at any price, so budget for a third-party warm-up tool if your domains are new.

Value assessment: Modelled at 10,000 emails a month, GMass Professional at $59.95 covers it with three or four connected Workspace mailboxes and costs less than most platform starter tiers once you account for the free verification and free secondary accounts. At 100,000 emails a month the arithmetic breaks down, not because GMass charges more but because you would need roughly fifty Workspace mailboxes at Google's own prices and an extension-based workflow to manage them, at which point a rotation-native platform is simply the right tool. Judged inside its range, GMass is the best capability-per-dollar in the category; judged outside it, it is the wrong architecture.

Strengths & limitations

Strengths

Sending happens through real Google mailboxes with your own authentication, which is the deliverability model every serious cold email operator eventually returns to.
Building a list from a Gmail search is a genuinely unique capability and repeatedly the reason people install GMass in the first place.
Free unlimited email verification and free secondary sending accounts under MultiSend remove two line items competitors bill for.
Flat per-user pricing with unlimited contacts and campaigns means budget certainty; nothing scales with list size.
A real REST API, webhooks, and triggered sending on a $39.95 plan is far more developer surface than a Gmail extension normally offers.
Bootstrapped, profitable, and around since 2015 with roughly a dozen employees, which in a category full of two-year-old vendors is a meaningful stability argument.
Zero learning curve for anyone already comfortable in Gmail, because the campaign is just a draft.

Limitations

No warm-up at all since 2023, so new domains need a separate tool and a separate bill before GMass is safe to run at volume.
Gmail's per-account caps (about 500 recipients a day on consumer Gmail, about 2,000 on Workspace) are a hard ceiling GMass cannot raise.
Gmail only. No Microsoft 365 support, no generic SMTP sending path for campaigns, and no plan to add them.
Reply management is Gmail labels plus a companion triage tool rather than a true team inbox with statuses, owners, and deal stages.
The Chrome extension dependency means the workflow lives or dies with Chrome and with whatever Google decides about extension permissions.
Email only, with no LinkedIn, calling, or task steps, so multichannel sequences require a second product entirely.
The interface is functional rather than pleasant, and the feature set has accreted over a decade in a way that shows.

Head-to-head comparisons

6 alternatives

GMass vs Mailmeteor

from $0 free, then $5.99 per user per month (Starter)

Both live inside Gmail and Google Sheets, but they are aimed at different people. Mailmeteor is cheaper, cleaner, privacy-first out of Paris, and starts at $5.99 a month with a genuinely usable free tier. GMass is denser, has the Gmail-search list builder, free verification, an API, and MultiSend rotation. Pick Mailmeteor for tidy low-volume merges and internal comms; pick GMass when the job is actual cold outbound across multiple mailboxes.

Full GMass vs Mailmeteor comparison

GMass vs Hunter Campaigns

from 0 euros free, then 34 euros per month (Starter)

Hunter bundles a large email-finding database with a modest sequencing tool, so you are buying data first and sending second, capped at three to twenty connected mailboxes by tier. GMass sells no data at all but sends far better, with unlimited connected accounts under MultiSend and free verification. Buy Hunter if finding the addresses is the hard part; buy GMass if you already have the list.

Full GMass vs Hunter Campaigns comparison

GMass vs Mailshake

from $25/user/mo (Starter, billed annually)

Mailshake is a proper web-app sequencer with a team inbox, lead catcher, and multichannel steps, priced per user well above GMass. GMass gives you more raw sending capability for less money but hands reply management back to Gmail. Teams that manage a shared pipeline want Mailshake; individuals who want power without a new interface want GMass.

Full GMass vs Mailshake comparison

GMass vs QuickMail

from $49/mo (Starter)

QuickMail is the closest philosophical match among the web apps: real mailbox connections, inbox rotation, and an obsession with deliverability, plus bundled warm-up through its own network. GMass matches the sending philosophy and undercuts the price but has no warm-up and no shared inbox. If you want the same approach with warm-up included and a proper multi-client UI, QuickMail is worth the premium.

Full GMass vs QuickMail comparison

GMass vs Instantly

from $37/mo

Instantly is built for unlimited mailboxes, bundled warm-up, and volume that GMass structurally cannot reach. GMass is built for a handful of real Gmail accounts at a fraction of the cost. Under about ten thousand sends a month from a few mailboxes, GMass wins on price and simplicity; above that, Instantly's architecture is the reason it exists.

Full GMass vs Instantly comparison

GMass vs Saleshandy

from $34/mo (Starter, billed annually)

Saleshandy offers unlimited email accounts, bundled warm-up, and a lead database on plans starting near GMass's price, all in a modern web app. GMass counters with free verification, free secondary accounts, the Gmail-search list builder, and a workflow that never leaves your inbox. Saleshandy is the safer default for a growing team; GMass is the better tool for a Gmail purist.

Full GMass vs Saleshandy comparison

Implementation & onboarding

Setup time: Under ten minutes for a first campaign: install the Chrome extension, authorize Gmail, connect a Google Sheet, and send. Custom tracking domain setup adds a DNS record and maybe an hour of propagation.
Learning curve: Very low to start because the campaign is a Gmail draft, but moderate to run well. The settings panel is dense, and the difference between a competent GMass user and a novice is mostly knowledge of pacing, tracking domains, and when not to send.
Onboarding: Entirely self-serve. There is no mandatory onboarding, no sales call, and no implementation fee at any tier including the hundred-user team plan. Documentation and an unusually deep blog carry most of the load.
Migration notes: Lists move as Google Sheets or CSVs in minutes and sequences are short enough to rewrite by hand. Because everything lives in Gmail labels and your own Sent folder, there is effectively nothing trapped in GMass if you leave, which is a real and underrated benefit. Historical campaign statistics do not export into another vendor's reporting.

Platform, API & security

Platforms: Chrome extension for GmailWeb-based campaign reports and settingsGmail mobile add-on for basic actionsREST API
API: REST API on paid plans covering campaign creation, list management, transactional and triggered sends, and statistics, plus webhooks and a Zapier integration.
Compliance: CAN-SPAM tooling including automatic unsubscribe links and opt-out suppressionGDPR-relevant processing terms; lawful basis for cold contact remains the sender's responsibilityGoogle OAuth restricted-scope verification for Gmail access
Data residency: US-hosted infrastructure; no published EU residency option.
SSO: Google sign-in only, since the product is authenticated through the Gmail account itself. No SAML SSO.
Security notes: Accounts connect over Google OAuth rather than stored passwords, including secondary MultiSend accounts. Because sending happens through Google's own servers, message content transits Google infrastructure rather than a third-party relay. No SOC 2 report is published as of this review.

Support & resources

Channels: Email support on all paid plansPriority email support on Professional and TeamIn-product help
Documentation: Extensive documentation plus a long-running technical blog that doubles as the category's deliverability reference, covering Gmail limits, tracking domains, and placement issues in unusual detail.
Community: Large informal user base among consultants, recruiters, and agencies; no official forum.

Company

Founded: 2015
Headquarters: United States
Ownership: Bootstrapped, founder-owned
Founders: Ajay Goel
Employees: Roughly a dozen (public revenue-tracker estimates)
Funding: No outside investment. Founded on approximately $10,000 of the founder's own money and grown on revenue; public trackers report roughly $8.6M annual revenue in 2024, up from $5.4M in 2023.

Timeline

2015Ajay Goel, previously founder of the email service provider JangoMail, launches GMass as a Chrome extension that turns Gmail into a mail-merge tool.
2017Adds automated follow-up sequences and the ability to build recipient lists directly from a Gmail search, the feature that becomes its signature.
2020Ships free built-in email verification and custom tracking domains with SSL, removing two costs competitors bill separately.
2023Discontinues its email warm-up feature, stating publicly that Google asked vendors to stop offering warm-up, and repositions around organic ramp-up.
2023Launches The Reply Project as a fast triage interface for working replies across connected accounts.
2024Public revenue trackers report approximately $8.6M in annual revenue with a team of about a dozen, entirely bootstrapped.

Integrations

Gmail and Google Workspace
Google Sheets
Google Contacts
Zapier
REST API and webhooks
Custom tracking domains via your own DNS
Salesforce and HubSpot via Zapier

Frequently asked questions

10 questions

What is GMass?

GMass is a Chrome extension that turns Gmail into a cold email and mail-merge platform. Campaigns are written as ordinary Gmail drafts, lists come from a Google Sheet or a Gmail search, and messages send through your own Google account with automated follow-ups, free verification, custom tracking domains, and inbox rotation across multiple connected mailboxes.

How much does GMass cost?

Standard is $29.95 a month or $249 a year, Premium is $39.95 a month or $349 a year, and Professional is $59.95 a month or $599 a year. Team plans are banded: five Premium users at $175 a month, ten at $295, twenty-five at $604, fifty at $1,125, and a hundred at $1,833. Contacts and campaigns are unlimited on every paid tier.

How many emails can I send with GMass?

As many as Google will let your accounts send. That is roughly 500 recipients a day from a consumer Gmail address and roughly 2,000 from a Google Workspace account. GMass does not add volume beyond that; what it adds is MultiSend on the Professional plan, which splits a campaign across several connected accounts so the effective ceiling is your account count multiplied by Google's cap.

Does GMass include email warm-up?

No. GMass shut its warm-up feature down in 2023, stating that Google asked it and other vendors to stop offering warm-up services. The vendor now recommends organic ramp-up, meaning low volumes to recipients likely to engage while reputation builds. If you are launching brand-new domains, plan to buy a separate warm-up tool.

Does GMass use an SMTP relay or my real mailbox?

Your real mailbox. Mail leaves through Google's own infrastructure from your authenticated account, so reputation accrues to your domain and mailbox rather than to a shared relay pool. This is the core deliverability argument for GMass and the reason it stays Gmail-only.

How does inbox rotation work in GMass?

The feature is called MultiSend and it is on the Professional and Team plans. You connect additional Gmail or Workspace accounts over OAuth and GMass splits a campaign evenly across them, so a thousand recipients across ten accounts is a hundred each. Follow-ups still come from the account that sent the first message, and if an account starts bouncing, remaining volume reroutes to the others. Only the primary account needs a paid subscription.

How does GMass handle unsubscribes, bounces, and replies?

GMass inserts an unsubscribe link, processes opt-outs automatically, and suppresses those addresses from future sends, which is the CAN-SPAM baseline. Bounces are detected and excluded from follow-up stages. Replies are recognized so follow-ups stop for that recipient, and both replies and bounces are filed under Gmail labels; The Reply Project gives you a faster triage view across accounts.

Is GMass legal for cold email under CAN-SPAM and GDPR?

GMass gives you the tooling required for compliance: unsubscribe links, automatic opt-out suppression, accurate sender identity because you send from your own account, and no misleading headers. It does not give you a lawful basis. Under CAN-SPAM, business cold email is broadly permitted if you identify yourself and honor opt-outs. Under GDPR, emailing EU individuals needs a legitimate-interest assessment and a real opt-out path, and that judgment is yours, not the vendor's.

Does GMass work with Outlook or Microsoft 365?

No. GMass is a Gmail product built on Google OAuth and the Gmail interface. If your business runs on Microsoft 365, look at Saleshandy, QuickMail, Instantly, or Smartlead instead.

Who owns GMass and is the company stable?

GMass was founded in 2015 by Ajay Goel, who previously ran the email service provider JangoMail, and is entirely bootstrapped with no outside investment. Public revenue trackers report roughly $8.6M in annual revenue in 2024 with about a dozen employees. In a category where vendors regularly shut down or get acquired, a decade-old profitable owner-operated business is a genuine point in its favor.

Editorial verdict

GMass is the best cold email tool for people who do not want a cold email platform. If you send from one to five real Gmail accounts, want free verification, want your replies in your normal inbox, and want a flat bill that never scales with list size, nothing else in this category is better value than $59.95 a month for Professional with MultiSend and free secondary accounts. The two things that should stop you are structural rather than fixable: Gmail's per-account daily cap sets a hard ceiling, and there has been no warm-up since 2023, so new domains need a separate purchase. Above roughly ten thousand sends a month, or on Microsoft 365, buy something else. Below that, GMass is a bootstrapped, profitable, decade-old product that quietly does more than tools costing three times as much.

Written by the SaaSTracker editorial team. Awards, when shown, are judged against the published criteria in our methodology.