Privacy Policy

Last updated: October 25, 2026 · Applies to prosignature.co, the ProSignature Chrome extension (version 0.3) and the Google Workspace connection

Who we are

ProSignature is an email-signature service at prosignature.co, with a free Chrome extension for Gmail. "We" on this page means ProSignature; "you" means you. For any question about your data, email porshianboti@gmail.com.

What we collect

Your account

You can create an account in two ways:

• Email and password. We store your email address and your password. The password is kept only as a one-way hash by our database provider, so nobody at ProSignature can read it. We also store your company name and the domain of your email address, which we use to set up your account, and whether you asked for marketing email.
• Sign in with Google. Google sends us a signed sign-in token with your email address, whether Google has verified it, your name, a link to your profile picture and Google's ID for your account. We keep these as your sign-in identity, with no password. Signing in with Google gives us no access to your Gmail or to anything else in your Google account.

The "Microsoft" button on the sign-up page does not connect to Microsoft: it creates an email-and-password account, and we receive nothing from Microsoft.

Your sign-in session is kept in your browser's local storage. Our database provider records when you sign in, with the IP address and browser type of the session, to keep accounts secure.

Your signature

Everything you put into the editor: your name, job title, phone and mobile numbers, email, website, address, social links, photo, logo, banner, button, sign-off, disclaimer, template and design choices. We also store the finished signature as HTML (the full version and a free-plan version), its name, and whether it is switched on.

So the Chrome extension can stay up to date, each signature also has a secret sync key, and we record the time of the extension's last automatic check, how many checks there have been and which version (free or Pro) it received. Your Home screen shows this as your "Live in Gmail" status.

Brand import

When you sign up with an email address on your company's own domain (not gmail.com, outlook.com, yahoo.com, hotmail.com or icloud.com), ProSignature tries to fill in your logo, colours, company name and social links from your public website. This runs in your browser, which contacts the services below directly. Each one receives your domain or your logo's web address, plus your IP address, as any website you visit does:

• to read your homepage: api.allorigins.win, corsproxy.io, r.jina.ai and api.microlink.io;
• to find a logo: unavatar.io, Google's favicon service (www.google.com/s2/favicons), DuckDuckGo's icon service (icons.duckduckgo.com) and image files on your own website;
• to read your logo's colours: images.weserv.nl, which is also used when you paste a logo address yourself.

Our free banner maker uses images.weserv.nl, unavatar.io and the DuckDuckGo and Google icon services in the same way. These services have their own privacy policies, and we don't control what they log.

Our image proxy. When a logo lives on another website, your browser asks our server (prosignature.co/img-proxy) to fetch that one image so it can be turned into a hosted copy. Only signed-in users can use it. Our server downloads the image (identifying itself as "ProSignature-logo-fetch"), checks that it really is an image, passes it straight back to your browser and keeps no copy. To prevent abuse it counts each user's requests for one minute, in memory only.

Your team

If you add people to your account, we store for each person: email address, name, job title, phone, the signature made for them (with and without the free plan's credit line), whether they are active, and when this last changed. If you add another admin in Settings, we store their email address and name. Please make sure the people you add know that you use ProSignature for their signature.

Each person also gets a secret key for their personal signature link, and we record when you copied or emailed their link, when it was last opened, and when their extension last checked in, how many times and which version it received.

The Google Workspace admin connection adds a little more, described in its own section.

Email preferences

Whether you asked to receive ProSignature tips and occasional offers by email, and when, where and with which wording you made or changed that choice, so we can prove it and honour an unsubscribe. See Marketing email.

Plan and settings

The plan, billing period and number of people you choose at checkout, any coupon code, and your account settings, such as how you roll signatures out to your team and whether the extension is installed. Never card details: see Payments.

Usage analytics and cookies

Our website and app use Google Analytics 4. It sets cookies in your browser (named _ga and _ga_ followed by an ID) to recognise a returning browser, and it receives the pages you view, your IP address, and your browser and device type. We don't show a cookie banner at the moment.

Inside the app we also send these events: signing up and signing in, and with which method; failed sign-ins and password resets, with a short error reason; installing or copying a signature (which template, and whether it is a Pro design) and whether its images were hosted; checkout steps (plan, billing period, number of people, price and any coupon code); seeing, clicking or closing the welcome offer; turning marketing email on or off; Google Workspace connection steps; unlinking browsers; the steps of deleting an account; and clicks on buttons such as choosing a plan, a banner or a review link. Personal signature link pages send whether the page loaded, whether the extension linked, and whether the signature was copied or saved into Gmail.

We don't send your name or email address to Google Analytics. One thing to know: when you ask to connect a company directory (Google Workspace or Microsoft 365), that event includes your company's domain name.

Free signatures carry one small clickable 'Created with ProSignature' line under the signature; Pro removes it. When someone clicks that line, they land on our website and Google Analytics records the visit as coming from an email signature.

To stop Google Analytics, block cookies for prosignature.co in your browser or install Google's opt-out add-on. Your browser also keeps your sign-in session and a cache of your signature images in local storage, and a coupon code you applied in session storage; these are not cookies.

Server logs

Netlify (our host) and Supabase (our database) log requests to our site and server, such as your IP address, the time and the address requested, to run and secure the service. When the Google Workspace connection is on, its daily job also logs each connected account's ID, domain and the number of signatures written or cleared.

The Chrome extension

Here is everything the ProSignature Chrome extension (version 0.3) and our website do with Gmail, in three parts: the first happens by default, the second only if you choose it, and the third is what never happens.

1. Adding your signature while you write (the default)

The extension runs on two websites only: mail.google.com and prosignature.co.

• In Gmail, when you open a new message, reply or forward, it inserts your signature above any quoted text. It looks at the message box only to find the right spot and to check whether Gmail's own signature is already there, so you don't get two. It never writes into Gmail's settings pages. Nothing from Gmail is stored or sent anywhere.
• On prosignature.co, while you are signed in, our website hands the extension your current signature and its sync key, and the extension copies the signature from your editor page, so an edit shows up in Gmail straight away (unless a signature is saved in Gmail's settings, which Gmail then uses instead). It ignores signatures whose images are not hosted on prosignature.co. Only prosignature.co can send the extension a signature or a key; no other website can talk to it.

What it keeps in your browser (Chrome's extension storage): your signature and its name; a secret sync key that links this browser to your signature; when it last checked, the last error and your plan; the "Add my signature when I compose in Gmail" switch; and, if you also saved the signature into Gmail's settings, a short fingerprint and the time of that save, so it can tell you when Gmail's copy is out of date.

How it stays up to date. The extension asks our server (our database at Supabase) for the latest version of your signature every 6 hours, when Chrome starts, when the extension is installed or updated, when you open Gmail (at most every 15 minutes), when you click "Check my account now" in its menu, and when prosignature.co links it. Each check sends only the sync key and the reason for the check, such as alarm (the 6-hour schedule) or gmail (you opened Gmail), plus, as with any web request, your IP address. Our server answers with your current signature (the free or Pro version, depending on your plan), or says the signature is switched off or the account is gone, in which case the extension erases its copy.

When the extension checks in, our server records the time of the last check, the number of checks and the plan it delivered. That is how your Home screen can show that your signature is live in Gmail.

The sync key is a secret. Anyone who has it can fetch your signature, though nothing else. To cut off every other browser, use Unlink other browsers in Settings: the key changes, and those browsers erase the signature at their next check.

This path needs no Google permission. Turn it off with the switch in the extension's menu; removing the extension deletes everything it stored. When first installed, the extension opens prosignature.co/app once.

2. Optional: saving your signature into Gmail's own settings

If you want Gmail itself to hold your signature, for example so the Gmail phone app can use it, you can save it into Gmail's settings. Three buttons do this, and each starts with a Google sign-in window:

• "Connect Gmail & install" on prosignature.co. Google asks you to allow two permissions: gmail.settings.basic (manage basic Gmail settings, including your signature) and userinfo.email (see your email address). Your browser then reads your email address from Google and writes your signature into your Gmail send-as signature. The access token Google issues stays in that browser tab's session storage for up to 45 minutes, so a second click doesn't ask again, and it is never sent to our servers. Your Gmail address is used to show where the signature went and to open Gmail; it is not saved to your account.
• "Apply to Gmail" in the extension's menu. The website also uses it when its own Google window can't open, and offers it when you delete your account so the saved signature can be cleared. Google asks for gmail.settings.basic only. The extension lists your Gmail send-as addresses to find your main one and writes the signature there. It doesn't keep the token or send it to us; it keeps only the fingerprint and time described above.
• "Save into Gmail settings" on a personal signature link. Google asks for the same two permissions as on prosignature.co. The page reads your email address from Google, warns you if it differs from the address the signature was made for, and writes the signature into that address's Gmail settings. The token is held only in the open page and is never sent to our servers.

What this permission can and can't do. gmail.settings.basic lets an app change basic mail settings. It does not let us read, send or delete your email. We use it only to write your signature, or to clear it when you ask.

It is a one-time save. Later edits don't reach Gmail's settings until you save again; the extension shows a "!" badge when a copy saved with its own Apply to Gmail button is out of date (it cannot see saves made on the website or a personal link). Gmail uses this signature for new messages, while replies and forwards follow a separate Gmail setting. The Gmail phone app uses it for new messages if you haven't set a separate mobile signature.

"Unverified app" screen. Until Google finishes reviewing ProSignature's use of this permission, Google shows an "unverified app" warning before the permission screen. You can go back and use the extension's default path instead, which needs no permission.

One more case. If Google's sign-in button can't load on the sign-up page, the backup "Continue with Google" route asks for the same two permissions just to fill in your email address, and you then finish with a password. The token is kept in the tab as above.

3. Nothing else

Neither the extension nor the website touches anything else in your Google account: no messages, contacts, calendar or files. Sign in with Google, if you use it, shares only your basic profile (see Your account). The only other way ProSignature can write a signature into Gmail is the Google Workspace admin connection, which a company's administrator has to set up.

Google API Services User Data Policy

ProSignature's use and transfer to any other app of information received from Google APIs will adhere to the Google API Services User Data Policy, including the Limited Use requirements.

In plain words: the information we get from Google (your basic profile from Sign in with Google, your email address, your Gmail send-as addresses and, for Workspace admins, the company directory) is used only to sign you in and to show and install the signatures you asked for. We don't sell it, use it for advertising or use it to train AI models, and no person at ProSignature reads it unless you ask us to for support, it is needed for security, or the law requires it.

The Chrome extension also follows the Chrome Web Store User Data Policy, including its Limited Use requirements.

Google Workspace admin connection

What it does. It lets a Google Workspace administrator put the right signature into every employee's Gmail without each person installing anything.

How it works. The Workspace administrator authorizes a ProSignature Google service account in the Google Admin console (domain-wide delegation) for two permissions: admin.directory.user.readonly (read the user directory) and gmail.settings.basic (change each person's signature). Our server uses it to act on behalf of the users on that domain, for signatures only.

Who can turn it on. A ProSignature account admin who signed in with Google using a Google Workspace address (not a personal Gmail address) and who is an administrator of that Workspace. Our server only ever acts within that admin's own domain.

• What it reads: for every user on the domain, including suspended ones, their email address, full name, main job title, phone number, whether they are a Workspace admin, and whether they are suspended or archived. People the admin adds, and new joiners found later, are saved to the team list.
• What it writes: each person's Gmail signature, replaced with the signature made for them. Employees are not asked one by one: their Workspace administrator authorizes this for the whole domain. If your company uses it and you have questions, ask your administrator or email us.
• The daily check: every day at 05:00 UTC, and when a connected admin opens the app, our server reads the directory again, clears the signature of people who were suspended or removed, rewrites signatures that changed (after a design edit or a plan change) and lists new joiners.
• The record we keep: for each mailbox, the email address, the status (written, cleared or failed), a short fingerprint of the signature written (the first 24 characters of a SHA-256 hash, not the signature itself), when it was written or cleared, and the last error. It tells us which mailboxes hold our signature, so we can update or remove them.
• Google tokens: our server creates short-lived Google access tokens (valid for an hour) for each call and doesn't store them. The service account's private key is kept only in our host's server settings.

To stop it, disconnect Google Workspace in the app's Settings and choose whether to remove the signature from every mailbox we maintain or leave them as they are, or remove ProSignature's entry under domain-wide delegation in the Admin console. When an account with this connection is deleted, we first try to clear every mailbox we wrote to.

Personal signature links

On a team plan, each person the admin adds gets a personal link: prosignature.co/s/ followed by a long random key. Employees don't need a ProSignature account to use it.

• What the page shows: that person's signature as it will appear under their emails (name, job title, phone, email and the company's branding), the company name and the name of the account admin, so they know who sent it. From there they can install it with the Chrome extension, by copy-paste, or by saving it into Gmail's settings.
• The key in the link is that person's own sync key. Opening the link in a browser with the extension links that browser to the person's signature, which then stays up to date exactly as described in Adding your signature while you write. A Chrome profile holds one signature at a time, so an admin who wants to preview a colleague's link should use a private window or a profile without the extension.
• What the admin sees: for each person, whether their link was copied or emailed, when it was last opened, and when their extension last checked in ("Live in Gmail"). Opening the page stores only the time it was opened on that person's record. Like the rest of our website, the page uses Google Analytics. It records the page as prosignature.co/s/, without the key or the person's name.
• Anyone who has the link can see that person's signature (the same details that appear under their emails) and could connect a browser to it. Send it only to that person. The page asks search engines not to index it.
• Turning a link off: removing the person from the team list stops their link working, and a browser linked with it erases the signature at its next check. To give someone who stays a new link, the admin clicks New link next to their name: the old link stops working, and their browser has to be linked again from the new one.

Images we host

When you save your signature, its images (logo, photo, icons, banner and buttons) are turned into PNG files in your browser and uploaded to our storage. Each one gets a public web address of the form prosignature.co/i/<your account ID>/<file name>.

• Public on purpose. Anyone with the address can load the image; that is how the people you email see it. Your account ID is a random code, not your name or email, but it is visible in those addresses.
• No open tracking. Every recipient gets the same address, and we don't use image requests to tell who opened your email.
• Kept after you delete your account. Emails you have already sent keep pointing at these images, so we don't delete them automatically: not when you change your signature, and not when you delete your account. If you want them removed, email us. Images in emails you already sent will then stop loading.

Payments

There is no payment processor yet. When you go through checkout or start the Teams trial, the card fields are checked in your browser only so the form can be submitted, and are then emptied. Card details are never stored, never sent to our servers or to analytics, and nobody is charged. We record your plan in your account and the checkout step in analytics, as described above. Before we take real payments, we will update this page, and a payment provider will handle card details.

Marketing email

• Off unless you opt in, by ticking the box at sign-up (it starts unticked) or in Settings → Email preferences.
• Sent through Resend, an email delivery service, which receives your email address and the message.
• Unsubscribe any time with the link in every marketing email (no login needed) or in Settings → Email preferences.
• What we keep: a record of every opt-in and opt-out (when, where and the wording you saw), and which campaign we sent you and when. We keep these even after you unsubscribe or delete your account: they are our proof of consent, and they make sure we never email you again. The computer we send from also keeps a send log and a do-not-email list.
• Emails about your account, such as password resets, are sent by our sign-in system and are not marketing.

Who else handles your data

These providers run parts of ProSignature for us, under their own privacy and security terms:

• Netlify hosts the website and runs our server functions (the image proxy and the Google Workspace connection).
• Supabase provides our database, sign-in, image storage and account emails.
• Google provides Analytics, Sign in with Google, the Gmail API when you save into Gmail's settings, the Directory and Gmail APIs for the Workspace connection, Google Fonts on some pages, and the favicon service used in brand import.
• Resend sends marketing email, only if you opted in.
• jsDelivr delivers the code library our app uses to talk to our database; like any website, it sees your IP address.
• The brand-import services listed above.

These providers may process data in the United States and other countries. We don't sell or rent your personal information, and we don't share it with advertisers. The people who run ProSignature can see account records to operate the service and answer support requests.

How long we keep it

We keep your data while your account exists. When you delete your account, it is removed from our database straight away, with the exceptions listed under What deletion does not erase. Copies can remain for a while in our providers' logs and backups, under their own retention schedules. Google Analytics keeps event data for the retention period set in our Analytics account; that data is not linked to your name or email address.

Your choices

• Edit or switch off your signature, brand and team list at any time in the app.
• Switch the extension off in its menu, or remove it.
• Use Unlink other browsers in Settings to disconnect every other browser from your signature.
• Marketing email is off unless you opt in; turn it off in Settings → Email preferences or with the unsubscribe link in any marketing email.
• Block Google Analytics as described under Usage analytics and cookies.
• There is no export button yet. To get a copy of your data, email us and we will send you what we hold.
• Depending on where you live, you may have the right to access, correct or delete your data, or to object to how we use it. Email us to use those rights. You can also complain to your local data protection authority.

Deleting your account

In the app, go to Home → Settings → Danger zone, click Delete my account and type DELETE. Here is what happens, in order:

1. If your account wrote signatures into employees' Gmail through the Workspace connection, we try to clear them. If we can't, we ask whether to delete anyway.
2. If the extension in this browser saved your signature into Gmail's settings, we offer to clear it there; Google asks for permission once.
3. The extension in this browser erases your signature and sync key. Extensions in other browsers erase theirs at their next check.
4. We delete your login, profile and signatures and, if you were the last person on the account, the company account with its brand, settings, team list, admins and Workspace record. Deleting the team list also turns off every personal signature link, and team members' extensions erase the signature at their next check. Then you are signed out.

What deletion does not erase

• Images we host for your signature (see Images we host). Email us to have them removed.
• Marketing consent records and the record of which campaigns we sent you, plus the send log and do-not-email list (see Marketing email).
• A signature saved into Gmail's settings with "Connect Gmail & install" on the website, or by a team member with "Save into Gmail settings" on their personal link. We don't track those saves, so deletion can't offer to clear them. Remove it in Gmail under Settings → See all settings → General → Signature.
• Google permissions you granted. Remove them at myaccount.google.com/permissions. Removing the extension does not do this, and it does not remove a signature already saved in Gmail's settings. Workspace administrators should also remove ProSignature's domain-wide delegation entry in the Admin console.
• Google Analytics data, provider logs and backups, as described under How long we keep it.

Changes to this policy

When we change what we collect or how we use it, we update this page and the date at the top.

Contact

Questions about this policy or your data: porshianboti@gmail.com.