How Mergeline keeps your lists private

Mergeline runs in your browser. Your lists, messages and results stay in your browser’s storage, and each email is sent through your own Gmail tab, so no Mergeline server receives them. If you buy Pro, our license server sees your license key and a random install ID. Mergeline adds no tracking pixels or link redirects.

Updated October 29, 2026. Facts about other tools come from their own pages and public reviews, read on October 29, 2026 and listed under Sources. Mergeline is our product.

Add to Chrome Read the privacy policy

Where does my data go when I send a campaign?

Three places, all yours, with no Mergeline server in the path.

Your browserLists, messages, results and your do-not-email list are stored here.
Your GmailEach email is sent from your account and saved in your Sent folder.
Each personGets a normal email with no tracking pixel and no redirected links.

Campaigns live in your browser’s extension storage, not in an online account, so there is nothing for us to lose, leak or sell. Here is everything that does leave your computer, from our privacy policy:

What leaves your computer, and where it goes
Data	Sent to	Why
The emails you send: recipient, subject and body	Gmail, in your own account	To deliver your emails, through Gmail’s own compose window by default.
Gmail searches for replies, opt-outs and bounces	Gmail, in your own account	To stop follow-ups for people who replied and skip bounced addresses. Results stay in your browser.
Email text you ask AI to write or improve	The AI provider you choose, with your own key	Only when you press an AI action. Nothing is sent if AI is off or you use your browser’s built-in model.
The domain part of addresses you check	Cloudflare’s public DNS service	Only when you press Check addresses, to find domains that cannot receive email.
A Google Sheets link you import	Google Docs	To download that sheet as a CSV file.
Your license key and a random install ID	Mergeline’s license server	Only if you buy Pro, to activate and check your license.

What does the Mergeline server see?

Only license data, and only if you buy Pro. The extension sends your license key and a random install ID to activate and check the license. It never sends your lists, your emails, your replies or your Gmail address.

For each purchase, the license server stores the license key, the Paddle transaction, customer and subscription IDs with the subscription status, the random IDs of the browsers where the key is active, and when the license was created. Paddle, our merchant of record, handles payment; we never see your card. The service runs on Cloudflare, which may keep short-lived request logs, including IP addresses, for security and reliability.

Why does Mergeline add no tracking pixels or link redirects?

Many mail merge tools insert an invisible image to record opens and route links through a server to record clicks. Mergeline does neither, on any plan:

Open counts are unreliable. Apple Mail Privacy Protection loads remote images for its users automatically, so a pixel “opens” whether or not the person read the email. Mailchimp calls open metrics unreliable for those users¹².
Deliverability. Cold email practitioners report that Gmail shows a warning banner on some emails with tracking images, with a one-click spam report, and advise turning open tracking off³⁴. That is their experience, not a Google statement. Google does ask senders to keep spam reports under 0.3%, and ideally under 0.1%⁵.
Your recipients’ privacy. A pixel tells the sender when and roughly where a person opened an email. A redirected link records every click on a third-party server. A personal email should not do either.
No server to receive them. Tracking needs a server that logs each request. Mergeline has none in the sending path, so there is nothing to log.

How does AI writing work without sending us your text?

AI writing is optional and off until you turn it on. You bring your own OpenAI, Anthropic or Google Gemini key, or use the model built into your browser. When you press an AI action, the text you asked about goes straight from your browser to the provider you chose. It does not pass through Mergeline. Your key is stored in your browser, and Chrome asks you to allow that provider’s address the first time you connect it.

What permissions does Mergeline ask for, in plain words?

These are Mergeline’s permissions. Those marked “asked when” are optional: Chrome asks you the first time a feature needs them.

Mergeline permissions, explained
Permission	When	What it is for
`storage` and `unlimitedStorage`	Always	Keep campaigns, lists, results, templates and settings in your browser, with room for big lists. Nothing is stored anywhere else.
`alarms`	Always	Send each email at its time with gaps between them, start scheduled campaigns, send follow-ups days later, and check for replies every 10 minutes.
`notifications`	Always	Tell you when a campaign finishes, when someone replies, when the daily limit is reached, and when sending pauses.
`scripting` and access to `mail.google.com`	Always, on Gmail only	Run the Gmail helper on mail.google.com only. It sends through Gmail’s compose window, finds replies, opt-outs and bounces with Gmail search, and adds the Mergeline button next to Send.
`identity`	Only if you choose Google sign-in	Sign in with Google to send through Gmail’s official interface instead of a Gmail tab. It asks for `gmail.send`, plus `gmail.readonly` only if you turn on reply detection.
Messages from `getmergeline.com`	Always	Lets our license pages check that Mergeline is installed and activate a Pro key. Other sites are ignored.
`docs.google.com` and `googleusercontent.com`	Asked when you import a Sheets link	Download that one sheet as a CSV file.
`cloudflare-dns.com`	Asked when you press Check addresses	Look up whether each email domain exists, so addresses that would bounce can be removed. Only domain names are looked up.
OpenAI, Anthropic or Google Gemini API	Asked when you connect your own AI key	Write or improve emails with the provider you chose.

Mergeline loads no remote code. All of its code ships in the package you install from the Chrome Web Store.

How is that different from a typical mail merge add-on?

Google sorts Gmail permissions, called scopes, by risk. Every scope that reads or changes mail, including gmail.readonly, gmail.modify, gmail.compose and full mail.google.com access, is restricted⁶. gmail.send, which can only send, is sensitive, not restricted⁷.

Apps that request restricted scopes must pass a yearly security assessment under the App Defense Alliance’s CASA framework, based on OWASP standards⁸⁹. Google’s guidance says that if you store or transmit restricted scope data on servers, you must go through that assessment⁷. Google also recommends that add-ons use narrow scopes instead of full mail access¹⁰.

As one Reddit post puts it, most mail merge tools “ask for a lot of permissions on user’s Google account data.”¹¹ Here is what common tools ask for, from their own pages:

What mail merge tools ask for, and where they keep data
Tool	Google permissions	Where data is kept
Mergeline, default mode	No Google account permissions. The extension runs on mail.google.com	Your browser
Mergeline, Google sign-in	`gmail.send` (sensitive), plus `gmail.readonly` (restricted) only for reply detection⁷	Your browser
GMass	Consent screen says it can “read and manage” your email¹²	Recipient addresses in the GMass database; content passes through its server¹³
YAMM	Read, compose and send email; all your Google Sheets; contacts; run when you are not present¹⁴	Uses Firebase as an external service¹⁴
Mailmeteor	Full Sheets access, send on your behalf, Firebase; more for follow-ups¹⁵	Recipients 180 days, events 90 days, templates and contacts with no set limit¹⁵
Mail Merge for Gmail	Send on your behalf, Drive, Contacts, drafts¹⁶	Firestore in its own Google Cloud project¹⁶
Streak	Gmail, Drive and Contacts APIs¹⁷	Google Cloud in the US; no email bodies¹⁷
Gmail mail merge	None: it is part of Gmail¹⁸	Your Google account

What if a Chrome extension is hijacked?

It happens. In December 2024 attackers took over several companies’ Chrome extensions, including Cyberhaven’s, and pushed malicious updates that stole session tokens and passwords¹⁹²⁰²¹. No extension can rule this out completely.

Mergeline limits the damage by design. It ships no remote code, its Gmail helper runs only on mail.google.com, and Sheets, DNS and AI access are asked for only when you use them. With no central database of everyone’s lists, there is no single store of contacts to steal.

How do I delete my data?

Erase or export in Settings. Download a backup or erase everything Mergeline stores, at any time.
Remove the extension. Uninstalling Mergeline deletes all of its data from your browser.
Disconnect Gmail or AI in Settings at any time.
License data. Write to us and we will show or delete the license data linked to your purchase. Deleting it deactivates the license.

Questions people ask

Can Mergeline read my Gmail inbox?

Its Gmail helper runs only on mail.google.com. It uses Gmail search to look for replies, opt-outs and bounces from the people in your campaigns, and keeps a short snippet of each reply for your report. That stays in your browser and is never sent to us.

Does Mergeline sell or share my data?

No. Mergeline never receives your lists or emails, and it runs no analytics, ads or third-party trackers in the extension.

Do I have to sign in with Google?

No. By default Mergeline sends through your open Gmail tab and asks for no Google account permissions. Google sign-in is an option for people who prefer Gmail’s official interface.

What does Mergeline store about me if I buy Pro?

Your license key, the Paddle purchase and subscription IDs, the random IDs of browsers where your key is active, and when the license was created. Paddle stores your billing details; we never see your card.

What happens to my data if I uninstall Mergeline?

It is deleted from your browser. Download a backup in Settings first if you want to keep your lists, templates or results.

Does my AI key or text go through Mergeline?

No. Your key is stored in your browser, and the text you ask about goes straight to the AI provider you chose.

Sources

Mailchimp: Apple Mail Privacy Protection FAQhttps://mailchimp.com/help/apple-privacy-faq/, checked October 29, 2026
Twilio docs: Apple inbox provider insightshttps://www.twilio.com/docs/email/concepts/inbox-provider-insights/apple, checked October 29, 2026
Reddit r/coldemail: does open tracking harm deliverabilityhttps://www.reddit.com/r/coldemail/comments/1gc01hj/does_open_rate_tracking_harm_deliverability/, checked October 29, 2026
The Growth List: deliverability without open trackinghttps://www.thegrowthlist.co/tactics/cold-email-deliverability-without-open-tracking, checked October 29, 2026
Gmail Help: email sender guidelineshttps://support.google.com/mail/answer/81126, checked October 29, 2026
Google Cloud Help: restricted scopeshttps://support.google.com/cloud/answer/13464325, checked October 29, 2026
Gmail API: choose Gmail API scopeshttps://developers.google.com/workspace/gmail/api/auth/scopes, checked October 29, 2026
Google Cloud Help: security assessment for restricted scopeshttps://support.google.com/cloud/answer/13465431, checked October 29, 2026
App Defense Alliance: CASAhttps://appdefensealliance.dev/casa, checked October 29, 2026
Google Workspace add-ons: scopeshttps://developers.google.com/workspace/add-ons/concepts/workspace-scopes, checked October 29, 2026
Reddit r/SideProject: privacy focused Workspace add-onhttps://www.reddit.com/r/SideProject/comments/oe39rc/built_a_privacy_focused_google_workspace_g_suite/, checked October 29, 2026
GMass FAQhttps://www.gmass.co/faq, checked October 29, 2026
GMass: what data does our server storehttps://www.gmass.co/blog/gmass-privacy-information-what-data-does-our-server-store/, checked October 29, 2026
YAMM help: what permissions are neededhttps://yamm.com/help/resources/data-security-and-policy/data-policy/data-access-what-permissions-are-needed-to-use-yamm/, checked October 29, 2026
Mailmeteor docs: privacyhttps://mailmeteor.com/docs/help/privacy, checked October 29, 2026
Digital Inspiration docs: permissionshttps://digitalinspiration.com/docs/mail-merge/permissions, checked October 29, 2026
Streak securityhttps://www.streak.com/security, checked October 29, 2026
Gmail Help: mail merge in Gmailhttps://support.google.com/mail/answer/12921167, checked October 29, 2026
Reuters: Cyberhaven hit by breachhttps://www.reuters.com/technology/cybersecurity/data-loss-prevention-company-cyberhaven-hit-by-breach-statement-says-2024-12-27/, checked October 29, 2026
TechCrunch: Cyberhaven Chrome extension hackedhttps://techcrunch.com/2024/12/27/cyberhaven-says-it-was-hacked-to-publish-a-malicious-update-to-its-chrome-extension/, checked October 29, 2026
Cyber Security Agency of Singapore alert AL-2024-147https://www.csa.gov.sg/alerts-and-advisories/alerts/al-2024-147/, checked October 29, 2026

Try Mergeline free in Gmail

60 emails a day free, with no card and no branding. Pro is $12 a month or $99 a year, with up to 7 follow-ups that stop on reply.

Add to Chrome

Gmail is a trademark of Google LLC. Other product names on this page are trademarks of their owners. Mergeline is not affiliated with, endorsed by or sponsored by Google or any other company named on this page.