Is our email content stored anywhere?

Not in our databases, logs or backups. When you trigger an action, the relevant text is sent over an encrypted connection and processed in memory. So that you can go back to a result, working copies are kept for a short time: in server memory for about 30 minutes in Gmail, and on your own device in Outlook. Nothing held in memory is written to disk, and the retention table in our Privacy Policy sets out each period.

Does Kerna read the inbox in the background?

No. Kerna operates exclusively on user-initiated actions. It does not passively scan, index, monitor or archive your inbox, calendar, contacts or any other mailbox data. Every interaction with your data requires an explicit action by the person using it. The one exception is a setting a person turns on: Scan automatically in Triage, in Outlook, repeats their triage scan at the interval they choose while Kerna is open, and never while it is closed.

What exactly does the AI provider receive?

The text of the message or draft you are acting on, plus your instruction, with personal data redacted first. The redaction happens inside Kerna’s own processing, so the redacted personal data never reaches the provider at all, and it runs on every request rather than being an option you enable. Your account identifiers, email address and billing data are never sent.

Is our data used to train AI models?

No, and not by OpenAI either. Your data is never used to train, fine-tune, retrain or improve any model, ours or anyone else’s. Our agreement with OpenAI includes Zero Data Retention terms: content Kerna transmits for inference is excluded from OpenAI’s abuse-monitoring logs and is not retained once the request has been served.

Where does the service run?

Kerna’s own infrastructure is in the EU: the application runs on Google Cloud Run in Belgium (europe-west1), with Firestore in Poland (europe-central2), and Kerna sp. z o.o. is a Polish company, so the controller is inside the EU as well. Inference is a separate question and the honest answer is separate too: our agreement is with OpenAI Ireland Limited, and that agreement permits transfers outside the EEA under Standard Contractual Clauses, so we do not claim the model call itself stays in the EU. Section 11 of the Privacy Policy sets out the sub-processor position and the safeguards covering it.

Can a Kerna employee read our messages?

No, and there is nothing stored for anyone to read. Personnel access to user data obtained through the platform APIs is prohibited except with your affirmative agreement for specific messages, where necessary to investigate abuse, or to comply with law. Because message content is never written to disk, there is no archive of your correspondence to be accessed, leaked or subpoenaed. That removes one class of risk; it does not remove the risk that exists while a request is being processed, which is what the encryption and access controls below are for.

Can a team leader see what their team is emailing?

No. Team leaders see usage — tokens spent and actions run per member, and on Enterprise a log of when those actions took place. None of it includes message content, subject lines or recipients, because Kerna does not store them anywhere.

Has any of this been independently reviewed?

Partly, and it is worth being precise about which part. The Gmail add-on has completed Google’s OAuth verification and holds a CASA Tier 2 Letter of Validation — an assessment carried out by an independent third party, which is what Google requires of apps that access Gmail data. On the Microsoft side the Outlook add-in holds Publisher Attestation, which is our own self-assessment published by Microsoft for customers to read; Microsoft does not independently verify it, and it is not Microsoft 365 Certification. The two are not equivalent and we do not present them as equivalent.

Will you sign a Data Processing Agreement?

Yes, and it is public. Our Data Processing Agreement is published at kerna.io/dpa, with our sub-processor list and the safeguards we rely on for international transfers — Standard Contractual Clauses are incorporated into our agreements with each sub-processor where a transfer requires them. It forms part of our Terms whenever Kerna is used for business, on every plan, and applies from the moment you start using Kerna or subscribe, with no separate signature. If your procurement process needs a countersigned copy, write to support@kerna.io and tell us which entity it should name.

How do we delete everything?

There is no email content to delete, because none was kept. For the rest, Kerna provides a data deletion endpoint that removes your profile, statistics and analytics data from all collections, and account data is deleted within 30 days of account deletion. One exception, and it is a legal one rather than a choice: billing records are kept for seven years for tax compliance, as the retention table below sets out. support@kerna.io will run the deletion on request.

Trust

Where your email goes

Kerna reads a message only when you press a button, redacts personal data before anything reaches the model, processes what remains in memory, and writes none of that content down. Your account, your plan and your settings are stored, because the service cannot run otherwise; your email is not. This page is the long version, with the source for every claim in our Privacy Policy. It exists so your security review can be a read rather than a meeting.

Talk to us about a review Read the Privacy Policy

Every claim on this page is sourced from our Privacy Policy or Terms. Last checked against them on 6 November 2026.

The short version

The ten questions your security review will ask

If you only read one section, read this one. Each answer points at the clause it comes from.

Is our email content stored anywhere?: Not in our databases, logs or backups. When you trigger an action, the relevant text is sent over an encrypted connection and processed in memory. So that you can go back to a result, working copies are kept for a short time: in server memory for about 30 minutes in Gmail, and on your own device in Outlook. Nothing held in memory is written to disk, and the retention table in our Privacy Policy sets out each period.
Does Kerna read the inbox in the background?: No. Kerna operates exclusively on user-initiated actions. It does not passively scan, index, monitor or archive your inbox, calendar, contacts or any other mailbox data. Every interaction with your data requires an explicit action by the person using it. The one exception is a setting a person turns on: Scan automatically in Triage, in Outlook, repeats their triage scan at the interval they choose while Kerna is open, and never while it is closed.
What exactly does the AI provider receive?: The text of the message or draft you are acting on, plus your instruction, with personal data redacted first. The redaction happens inside Kerna’s own processing, so the redacted personal data never reaches the provider at all, and it runs on every request rather than being an option you enable. Your account identifiers, email address and billing data are never sent.
Is our data used to train AI models?: No, and not by OpenAI either. Your data is never used to train, fine-tune, retrain or improve any model, ours or anyone else’s. Our agreement with OpenAI includes Zero Data Retention terms: content Kerna transmits for inference is excluded from OpenAI’s abuse-monitoring logs and is not retained once the request has been served.
Where does the service run?: Kerna’s own infrastructure is in the EU: the application runs on Google Cloud Run in Belgium (europe-west1), with Firestore in Poland (europe-central2), and Kerna sp. z o.o. is a Polish company, so the controller is inside the EU as well. Inference is a separate question and the honest answer is separate too: our agreement is with OpenAI Ireland Limited, and that agreement permits transfers outside the EEA under Standard Contractual Clauses, so we do not claim the model call itself stays in the EU. Section 11 of the Privacy Policy sets out the sub-processor position and the safeguards covering it.
Can a Kerna employee read our messages?: No, and there is nothing stored for anyone to read. Personnel access to user data obtained through the platform APIs is prohibited except with your affirmative agreement for specific messages, where necessary to investigate abuse, or to comply with law. Because message content is never written to disk, there is no archive of your correspondence to be accessed, leaked or subpoenaed. That removes one class of risk; it does not remove the risk that exists while a request is being processed, which is what the encryption and access controls below are for.
Can a team leader see what their team is emailing?: No. Team leaders see usage — tokens spent and actions run per member, and on Enterprise a log of when those actions took place. None of it includes message content, subject lines or recipients, because Kerna does not store them anywhere.
Has any of this been independently reviewed?: Partly, and it is worth being precise about which part. The Gmail add-on has completed Google’s OAuth verification and holds a CASA Tier 2 Letter of Validation — an assessment carried out by an independent third party, which is what Google requires of apps that access Gmail data. On the Microsoft side the Outlook add-in holds Publisher Attestation, which is our own self-assessment published by Microsoft for customers to read; Microsoft does not independently verify it, and it is not Microsoft 365 Certification. The two are not equivalent and we do not present them as equivalent.
Will you sign a Data Processing Agreement?: Yes, and it is public. Our Data Processing Agreement is published at kerna.io/dpa, with our sub-processor list and the safeguards we rely on for international transfers — Standard Contractual Clauses are incorporated into our agreements with each sub-processor where a transfer requires them. It forms part of our Terms whenever Kerna is used for business, on every plan, and applies from the moment you start using Kerna or subscribe, with no separate signature. If your procurement process needs a countersigned copy, write to support@kerna.io and tell us which entity it should name.
How do we delete everything?: There is no email content to delete, because none was kept. For the rest, Kerna provides a data deletion endpoint that removes your profile, statistics and analytics data from all collections, and account data is deleted within 30 days of account deletion. One exception, and it is a legal one rather than a choice: billing records are kept for seven years for tax compliance, as the retention table below sets out. support@kerna.io will run the deletion on request.

The request path

What happens when someone presses a button

Four stages. Personal data is stripped out at the second one, before anything is transmitted, and what remains exists only for as long as the request takes.

01
Nothing happens until you act
The add-in sits in the ribbon or sidebar doing nothing. There is no scheduled job on our servers, no sync, no index. A message is touched only when someone presses Summarize, Reply, Translate, Compose, Extract or Rewrite. In Outlook, a person can also turn on Scan automatically in Triage, which repeats their triage scan while Kerna is open.
02
Personal data is redacted first
Before anything leaves Kerna, personal data is redacted from the message content. This runs inside our own processing on every request — not as an option you enable — so the redacted data never reaches the inference provider at all.
03
The rest travels encrypted
What remains is sent to our inference provider over an encrypted connection, protected with TLS 1.2 or higher, and only the minimum text context the feature needs is sent.
04
Processed in memory, never written to a database
The content is processed in memory and is never logged or written to a database. So that you can go back to a result, working copies are kept for a short time: in server memory for about 30 minutes in Gmail, and on your own device in Outlook, for a few minutes to 30 days depending on the item. Nothing held in memory is written to disk.

Never collected

What is never written down

Kerna reads these to do the job you asked for. None of them is stored, logged, cached or written to any persistent storage afterwards — which is a different and stronger statement than deleting them on a schedule.

Email message bodies, subjects, or headers
Sender or recipient email addresses from processed emails
Attachment content or metadata
AI-generated summaries, replies, translations, or drafts
Calendar event content, contact details, or spreadsheet data accessed during user-initiated actions
Account passwords or OAuth refresh tokens beyond what is required for active session management

Retention

What is kept, and for how long

The full table from Section 12 of the Privacy Policy, unedited.

Data category	Retention period
Email content (processed)	Not written to our databases, logs or backups. Working copies in server memory: about 30 minutes in the Gmail add-on, a few minutes for shared mailboxes. Outlook add-in: on your device, from a few minutes to 30 days depending on the item (see 9.3).
Account data (email, name)	Kept until you use Delete my data, which takes effect immediately, or ask us to delete it (within 30 days). Uninstalling the add-on does not delete it, and if you use Kerna again the same record is used. After Delete my data, using Kerna again creates a new record.
Subscription and billing data	Retained while your subscription is active. Billing records retained for 7 years for tax compliance.
Usage metrics (token counts)	Current-period token count: reset each billing cycle. Monthly usage counts: kept until you delete your data. On the free plan, Delete my data keeps the current month's token count until the end of that month, under a keyed hash of your email address rather than the address itself, so that deleting and re-creating an account does not reset the free allowance.
Settings and content you create in Kerna (2.4)	Kept until you change or remove them, or delete your data. Gmail Done list: each entry stops applying after 30 days and is then removed the next time you open Inbox Triage.
Analytics data (GA4)	Retained for 14 months per Google Analytics default configuration.
Add-on usage events (keyed hash, 2.6)	Deleted after 90 days.
Welcome, early access and contact records	Kept until you delete your data or ask us to delete it.
Email contact record (Brevo)	Retained while your account is active. Deleted from Brevo automatically when your account is deleted. If you unsubscribe, it is kept only so that we do not email you again.
Team status for Outlook shared mailboxes	Status of a conversation: deleted 90 days after it is marked done, otherwise one year after the last change. Record of who has opened a shared mailbox with Kerna: deleted 180 days after the last use, or when the person leaves the team. Assignment rules: kept until a leader changes them; a team member is taken out of them when they leave the team. Custom statuses: kept until a leader removes them. New emails nobody has handled yet, listed for the team's dashboard: replaced at each count, deleted 30 days after the last. All of it is deleted with the team owner's account.
Send to… destinations and send log	Destination settings: kept until the destination is deleted, and deleted with the account of the team owner (or of the user, when not on a team). Send log: each entry is deleted after 90 days, and a team member's entries are deleted sooner if they delete their data while on the team.
Team membership and invitations (2.10)	Kept while you are on the team or until an invitation is accepted, declined or withdrawn, and deleted with the team owner's account.
Partner Programme: applications, partners and their dashboard users (2.11)	An application that is not accepted is deleted 12 months after our decision. A partner's account and the details of the people with access to its dashboard are kept while the partner agreement lasts and then until claims under it are time-barred. Records needed for accounting and tax (commission entries, statements, invoice numbers, payments, the record of the terms accepted and the withholding tax documents) are kept for 7 years, as billing records are.
Partner Programme: client attribution and deal registrations (2.12, 2.13)	Attribution records and the commission entries that name a client's company or domain are accounting records, kept for 7 years, also after Delete my data. A deal registration is kept while it is open and then with the partner's records.

Sub-processors

Who else touches anything

Six, each receiving only what its function needs. Stripe never sees an email; OpenAI never sees billing data.

OpenAI

AI inference

The text of the email or draft you are acting on, plus your instruction, only when you trigger an action. Encrypted in transit, processed transiently, not stored, not used for training. Account identifiers, email address and billing data are never sent.

Stripe

Payment processing

Email address for customer identification. All payment details are handled directly by Stripe; Kerna never sees a card number.

Google Firebase

Authentication, database, hosting, abuse protection

Account data, subscription status, usage metrics and preferences; once you are signed in to the website, browser and device signals for reCAPTCHA (App Check). No message content.

Google Analytics

Website analytics

Anonymous, aggregated website usage data, subject to consent. Website only — the add-in is not analytics-instrumented against your mailbox.

Sentry

Error tracking and performance monitoring

Hashed user identifiers, error stack traces and operational metadata. No email content, recipients or subject lines.

Brevo

Sending our emails to you

Your email address, sign-up platform and whether you signed up on our website or in Gmail or Outlook, interface language, plan, account creation and last-use dates, and whether you agreed to marketing emails, plus delivery, open and click records for the emails it sends. No name, no email content, nothing from your mailbox. Stored in the EU. For Partner Programme emails, the partner's address and the email itself.

Mailbox access

Exactly what Kerna can reach

Every scope the add-ins request, matching Section 8 of the Privacy Policy as it stood on the review date at the foot of this page, with what each one is used for.

Google Workspace

Twelve scopes, the set the add-on manifest requests. Google asks for the optional ones separately, so you decide which to grant. The identifiers below are Google’s own OAuth scope strings, each one prefixed https://www.googleapis.com/auth/ — the same strings the Marketplace listing is generated from, so the two lists can be checked against each other.

userinfo.email: Confirm your identity and read the address you signed in with.
gmail.addons.execute: Run the Kerna panel inside Gmail. On its own it gives no access to mail.
gmail.addons.current.message.action: Act on the message you have open, when you trigger a function from the panel.
gmail.addons.current.message.readonly: Read the message you have open, when you trigger a function from the panel.
gmail.readonly: Read the rest of the thread and its attachments for Summarize, Translate, Extract and Rewrite.
gmail.compose: Create a draft in your compose window. Google’s own wording for this permission is wider than what Kerna does with it — see the note under the table.
gmail.addons.current.action.compose: Put the text Kerna wrote into the email you are writing, when you press Insert into email in Gmail’s compose window. Kerna does not read the draft. Google’s own wording for this permission is wider too — see the note under the table.
calendar.events: Create an event from a date and time found in a message, only when you confirm it.
calendar: Check your calendar for a conflict at the time an extracted event would fall.
tasks: Create a task from an action item when you ask for one.
contacts: Look up or add a contact when you request a contact action.
drive.file: Write the Google Sheet or Google Doc an extraction exports to. It reaches only files Kerna itself creates, never the rest of your Drive.

Microsoft 365

Ten scopes. On Outlook no permission to send mail is requested at all — unlike Gmail, where writing a draft needs the scope described under the table.

Mail.Read: Read the current message when you trigger an action.
Mail.ReadWrite: Insert generated drafts into your compose window.
Calendars.ReadWrite: Check availability and create events from dates you extract, on explicit confirmation.
Tasks.ReadWrite: Create tasks from action items when you ask for them.
Contacts.ReadWrite: Look up or add contacts when you request a contact action.
People.Read: Read your relevant people list to support contact actions.
MailboxSettings.ReadWrite: Read your time zone, language and working hours so extracted dates and conflict checks are right for your region. Write is used only to apply a setting you change yourself inside Kerna.
Mail.Read.Shared: Read the message you are working on in a shared or delegated mailbox your organisation has already granted you.
Mail.ReadWrite.Shared: Create or update a draft, and file a message you have triaged, in a shared or delegated mailbox you already have permission to use, and set Kerna's categories there, including the team status, the assigned person and Done (Kerna).
User.Read: Confirm your identity and read your name and email at sign-in.

Kerna cannot reach a mailbox your organisation has not already granted you access to, and it does not send mail. Be aware of one wording difference you will see for yourself: Google’s own labels for the two Gmail scopes an add-on needs in order to write a draft and to put text into the email you are writing are “Manage drafts and send emails” and “Manage drafts and send emails when you interact with the add-on”, so those phrases appear on our Marketplace listing. Kerna uses them to create the draft and to insert text, and never to send. On Outlook no send permission is requested at all.

Assurance

What has been assessed, and by whom

CASA Tier 2 Letter of Validation

The independent security assessment Google requires of applications that access Gmail data. Held alongside completed Google OAuth verification.

Microsoft Publisher Attestation

A self-assessment we completed and Microsoft publishes for customers to read. Microsoft does not independently verify the answers, and it is not Microsoft 365 Certification — so it belongs on this page as a disclosure, not as an audit.

Google API Limited Use and Microsoft APIs Terms of Use

Data from both platforms is used only to deliver the user-facing features, is never sold or transferred, is never used for advertising, and only the minimum scopes needed are requested.

Encryption and access control

TLS 1.2 or higher in transit, AES-256 at rest in Firestore, secrets in Firebase Secret Manager rather than source, role-based access to production, and document-level Firestore rules. A breach affecting personal data is notified within 72 hours under GDPR Article 33.

AI content is labelled

Every reply, email or summary Kerna writes ends with invisible characters that software can recognise as Kerna’s AI mark, in line with the transparency direction of the EU AI Act; anyone can check a text at kerna.io/ai-marker. The mark is lost if that part of the text is deleted or stripped, so it is a signal rather than proof. A visible line can be added to generated messages (always on for Starter), and exported files are marked as well.

GDPR rights

Access, rectification, erasure, restriction, portability and objection, exercised through privacy@kerna.io. The legal bases are set out in the Privacy Policy.

Rollout

What IT needs to know before rollout

Outlook requires a mailbox hosted by Microsoft: Microsoft 365, Exchange Online or Outlook.com. Microsoft does not load add-ins on accounts connected over POP or IMAP, and mailboxes on an on-premises Exchange server are not supported.
On the client side Kerna runs in Outlook on the web, the new Outlook for Windows and Mac, and classic desktop Outlook.
A Microsoft 365 administrator can deploy the add-in to the whole organisation from the Microsoft 365 admin center; a Google Workspace administrator can install the Gmail add-on for the entire domain from the Google Workspace Marketplace.
Each person still signs in individually to link their Kerna plan. Authentication is Google OAuth or Microsoft sign-in — Kerna never creates, manages or stores a password.

Send us the questionnaire

Send us your security questionnaire or your IT team’s questions. We will answer them against the same sources this page cites, and add anything that turns out to be missing here.

Talk to us Privacy Policy Terms