Privacy policy
Effective date: 6 November 2026
KLO Mail ("the app") is an email and calendar app for Mac, iPhone and iPad. Diego is KLO's own assistant, which runs on a Mac and files KLO's mail. Both are made by KLO Technical Services Limited, trading as KLO Development Services, company number 16105032, registered office 23 Brook Road, Bomere Heath, Shrewsbury, Shropshire, SY4 3PU ("KLO", "we").
KLO Mail and Diego sign in to Gmail through the same registration with Google. This policy explains what they do with the information they get from your Google Account, and where it goes.
The short version
- We never receive your mail. KLO runs no server for the app. Your mail goes between your device and Google, and is kept on your device.
- AI only for features you use. KLO Mail sends a message to Anthropic's Claude only when you ask it to rewrite a draft. Diego sends parts of KLO's own mail to Claude to file it, summarise it and suggest replies. The details are below.
- No advertising, no analytics, no tracking. Your Google data is never sold, never used for advertising, and never used to train general AI models.
What KLO Mail asks Google for
| Permission | Why |
|---|---|
| Read, change and organise your mail (gmail.modify) | To show your mail and keep it up to date; to mark it read, flag, label, move, archive or move it to Trash when you choose; to save your drafts; and to take mail from senders you trust out of Spam |
| Send mail as you (gmail.send) | To send the messages you write, and the read receipts and unsubscribe emails you choose to send |
| Basic mail settings (gmail.settings.basic) | Only to add a filter that keeps a sender out of Spam, when you choose Never Junk This Sender. The app doesn't read or change any other setting |
| Your calendars (calendar) | Asked for only if you choose Allow Calendar Access on the Calendar screen. To show your calendars and events, and to add, change, delete or answer the events you choose. Google tells the guests of an event you change |
The app never deletes mail permanently: mail you delete goes to Gmail's Trash. It doesn't use any other part of your Google Account.
KLO Mail works with Microsoft 365 mailboxes too. What it keeps, and where it sends it, is the same for them.
What is kept, and where
| What | Where it's kept |
|---|---|
| Your mail: who it's from and to, subjects, previews, labels, the text of messages you've opened, and your drafts | On that device only, in the app's own storage |
| Calendar events | Not kept: they're shown while the Calendar screen is open |
| Your Google sign-in | In the device's keychain (Apple's encrypted store), on that device only. On a Mac, Diego reads it from there (see Diego) |
| Settings that follow you to your other devices: nicknames, favourite folders, senders you've marked Never Junk, templates, signatures, muted conversations (with their subject), the reactions you've sent, categories, calendar feeds you've added, and corrections the app has learned | In your own iCloud, under your Apple Account. Not your mail |
| Counts of unread, flagged, draft and scheduled messages, for the KLO Suite app | In your own iCloud Drive, in the KLO apps' shared folder. Counts only |
| On a Mac, recent mail for Diego: your inbox from the last 14 days (up to 400 messages) and your sent mail from the last 21 days (up to 300), each with up to 4,000 characters of its text and the names of its attachments | In a file on that Mac that only your user account can open. It's replaced each time the app refreshes |
| Attachments Diego asks KLO Mail to save, such as invoices | On that Mac, in the Downloads folder, under "Diego Imports" |
Apple holds your iCloud under your own agreement with Apple. KLO can't see it.
Where your Google data goes
- Google, to read and change your mail and calendar.
- Anthropic (Claude), when you ask KLO Mail to rewrite a draft. Only when you choose Rewrite in the message you're writing, or ask Diego to draft a reply or a forward in KLO Mail. It sends the message you're answering or forwarding (who it's from and to, the date, the subject and up to 12,000 characters of its text), your own draft, and the tone you chose. It uses the Anthropic API key set up in Diego; with no key, nothing is sent. The answer goes into your draft, and nothing is emailed until you send it.
- Senders' own websites, only when you choose. Pictures in a message load only when you choose Load Images, or turn on loading them automatically. They come straight from the sender's server, which then sees your internet address. One-click unsubscribe tells the sender you've unsubscribed, when you press it.
- Apple, for your settings in iCloud, as above.
- Nobody else. No KLO server, no analytics, no crash reports and no advertising.
Diego
Diego is KLO's own assistant. It runs on one Mac, works on KLO's own Gmail mailbox, and isn't offered to anyone else.
- What it asks Google for: to read, change and organise mail (gmail.modify). On that Mac it uses the sign-in KLO Mail keeps in the keychain.
- What it does: it reads who mail is from, its subject, date and preview; files mail into labels; archives it; and moves mail from senders KLO has listed to Gmail's Trash. It never sends email through Google and never deletes mail permanently. Replies it suggests are saved as drafts in KLO Mail, for a person to check and send.
- What it sends to Anthropic (Claude), through KLO's own Claude account:
- to file mail: who it's from, the subject, the date and up to 300 characters of its preview, with the mailbox's label names;
- to find mail still waiting for an answer: who KLO wrote to, the subject, the date and KLO's own preview;
- to summarise new mail, prepare a morning briefing, chase replies and suggest draft replies: who it's from and to, the subject and the text of the message;
- invoices attached to mail, to read the invoice.
- What it keeps, on that Mac and in that Mac's backups: records of what it filed (sender, subject and label), its daily job reports and its summaries. Some summaries are saved as notes in KLO Notes and Apple Notes. They are kept until deleted.
- It may read a summary aloud, using speech made on that Mac.
How we follow Google's rules (Limited Use)
KLO Mail's use and transfer of information received from Google APIs to any other app will adhere to the Google API Services User Data Policy, including the Limited Use requirements. The same applies to Diego. In particular:
- Google data is used only to provide the features described in this policy, which you can see and use.
- It is passed to others only as described here (to Anthropic for the AI features, and to Apple for iCloud), to comply with the law, or as part of a merger, acquisition or sale of KLO's business, with notice to you.
- It is never sold, and never used for advertising, including personalised or retargeted adverts, or to decide whether anyone is credit-worthy.
- Nobody at KLO reads your Google data, unless you ask us to (for example, to answer your support request), it's needed for security, such as investigating abuse, or the law requires it.
- It is never used to develop, improve or train general AI or machine-learning models. Anthropic doesn't train its models on it: KLO Mail's rewrite uses Anthropic's commercial API, and model training is turned off on the Claude account Diego uses.
Taking away access, and deleting
- In KLO Mail: Settings › Accounts › Remove This Mailbox. It deletes your Google sign-in from the device, and that mailbox's mail, drafts and scheduled messages from the app. Your settings in iCloud stay, in case you add the mailbox again.
- At Google: removing the mailbox in the app doesn't cancel KLO Mail's access with Google. To do that, open your Google Account, choose Security, then your connections to third-party apps and services (myaccount.google.com/connections), choose KLO Mail and delete its connections. After that, neither KLO Mail nor Diego can reach your mailbox.
- Your mail stays in Gmail. Removing KLO Mail deletes none of it.
- To ask us to delete anything Diego has kept about you, for example because you've emailed KLO, email [email protected].
Information about other people
Email holds information about the people who write to you and the people you write to. KLO Mail and Diego handle it only as this policy describes.
Your rights
Support emails. If you email us at [email protected], we use your email only to answer you.
- We keep it for as long as we need to deal with it, then delete it.
- If it leads to work for you, it becomes part of our business records for that work.
- You can ask us to see or delete it.
You can complain to the Information Commissioner's Office (ico.org.uk) if you think your information has been handled wrongly. We'd be grateful for the chance to put it right first.
Children
KLO Mail and Diego are business tools. They aren't meant for children.
Changes
If this policy changes, the new version is put on this page with its date.
Contact
KLO Development Services, 23 Brook Road, Bomere Heath, Shrewsbury, Shropshire, SY4 3PU. Email: [email protected].