Privacy Policy

bytemail is a mail client for macOS. It runs on your Mac and talks directly to your mail provider. We — Sergey Karakhanyan, the developer and operator of bytemail and of this website ("bytemail", "we") — do not run servers that receive, store or process your mail. This policy explains exactly what the app and this website do with data.

1. Data the bytemail app handles

To work as a mail client, the app accesses the following on your behalf. All of it is processed and stored locally on your Mac:

• Mail content — messages, headers, attachments, folders, read/unread state and drafts from the accounts you add. A local cache is kept in an SQLite database in ~/Library/Application Support/ByteMail so mail can be read offline and searched on-device.
• Account details — your email address, the display name your provider reports, server settings, and the label and colour you choose.
• Credentials — passwords, app passwords and OAuth refresh tokens are stored only in the macOS Keychain. Gmail, iCloud and Yahoo accounts connect with an app password you create in your provider's account settings and can revoke there at any time. If you sign in with Microsoft, that happens in your browser on Microsoft's own page and bytemail never sees your Microsoft password.
• Your writing style — to make suggested replies sound like you, the app notes the greetings, sign-offs and tone you use in your sent mail. This short profile is kept in the local database with the rest of your mail.
• Contact photos (optional) — if you allow access to Contacts, the app looks up a sender's photo on your Mac by email address. Nothing from your address book is transmitted anywhere.

None of this is sent to bytemail or to any third party. We have no ability to access it.

Apple Intelligence features. On macOS 26 with Apple Intelligence turned on, the app uses Apple's on-device language model (Foundation Models) for conversation summaries, suggested replies, Rewrite in the composer and a second look at which messages need a reply. The model runs on your Mac: the text it reads is not sent to Apple, to us or to anyone else. You can turn these features off, together or one by one, in Settings › AI.

Your own AI model (optional, off by default). In Settings › AI › AI model you can have these features use a model of your choosing instead: Claude (Anthropic), OpenAI, OpenRouter (which passes it on to the maker of the model you pick), or any server that speaks OpenAI's API, such as LM Studio or Ollama on your Mac. You add your own API key, which is stored only in your Mac's Keychain. When you open a conversation that gets a summary or suggested replies, or use Rewrite, that text — and, for replies in your own voice, a few short excerpts of your sent mail — is sent directly from your Mac to the provider you picked, under your agreement with them and their privacy policy, not ours. It never passes through our servers. The background second look at To Reply only ever runs on a model on your Mac. Switching back to Apple Intelligence or removing the key stops it.

iCloud settings sync (optional, off by default). If you turn it on, the app stores your account settings (addresses, server settings, names and colours), signatures, aliases, templates, rules and some preferences in your own iCloud account through Apple's iCloud key-value storage, so your other Macs can pick them up. It never syncs mail, contacts, passwords or tokens — each Mac signs in to each account itself. That data is held by Apple under Apple's privacy policy; we cannot access it. Turning sync off stops it.

AI apps (optional, off by default). In Settings › AI you can let AI apps on your Mac that use the Model Context Protocol (MCP), such as Claude, Claude Code, Cursor or LM Studio, work with the accounts you choose. The AI app starts the bytemail app as a local helper and exchanges data with it on your Mac; bytemail itself sends nothing anywhere for this. Whatever the AI app reads — messages, attachments, addresses — is then handled by that app and, if its model runs in the cloud, by its provider, under their own terms and privacy policies, not ours. One-time codes and sign-in or password-reset links are hidden from AI apps by default, Spam and Trash are never shared, and sending always asks you in bytemail first. A record of what AI apps did (for Undo) stays on your Mac. Turning the setting off stops all of it.

2. Network connections the app makes

• Your mail provider, over IMAP and SMTP with TLS, to read and send your mail.
• Microsoft's sign-in endpoint, only if you add an account with "Sign in with Microsoft", to obtain and refresh access tokens. No mail content is sent to it.
• A sender's own website, to fetch its public logo or icon for the sender's avatar: the logo its domain lists in DNS for mail apps (BIMI), looked up through your Mac's usual DNS resolver, else the icon on its website. The request carries no identifiers and nothing about you or the message. It is never made for mail in Spam.
• Gravatar (gravatar.com, run by Automattic), to fetch the picture a sender set up there, unless you turn off "Find photos on Gravatar" in Settings › General. The request contains a one-way hash (SHA-256) of the sender's address, so Gravatar can tell which addresses you get mail from; it contains nothing about you or the message. It is never made for mail in Spam.
• Image hosts referenced inside a message, only after you choose to load remote images for that message or turn on "Always load remote images". Loading remote images can tell the sender that you opened the message; that is why it is off by default.
• A mailing list's unsubscribe address, only when you press Unsubscribe: a one-click request (or an unsubscribe email from your own account) that the list itself provided, sent without cookies.
• The AI provider you choose (for example api.anthropic.com, api.openai.com or openrouter.ai), only if you set up your own model in Settings › AI › AI model, to write summaries, suggested replies and rewrites, as described in section 1.
• Apple iCloud, only if you turn on iCloud settings sync, as described in section 1.
• bytemailapp.com, to check whether a newer version of the app exists. The request contains the app version and macOS version and no identifier tied to you.
• bytemailapp.com, to check your licence: when you activate the app and then about twice a day. The request contains your licence key, an identifier for this Mac (a one-way hash of its hardware ID, never the ID itself), the Mac's name as set in System Settings, and the app version — so that a licence can be used on 5 devices and you can see and remove them. It contains nothing about your mail or mail accounts.

That is the complete list. The app contains no analytics, advertising or tracking SDKs and sends no crash reports automatically: after a crash it offers to prepare a report as an ordinary email that you can read, and nothing is sent unless you press Send.

3. Gmail and Google accounts

Gmail and Google Workspace accounts connect over standard IMAP and SMTP with an app password, like any other provider. Your mail is handled exactly as described in section 1, and you can revoke the app password at any time in your Google Account under Security › App passwords.

4. Microsoft user data

If you connect an Outlook, Microsoft 365 or Exchange Online account, bytemail requests IMAP.AccessAsUser.All, SMTP.Send, offline_access and basic sign-in scopes (openid, email, profile). The same rules apply: the data is used only on your device to provide the mail client, stays on your Mac, and is never sent to us. You can revoke access at account.microsoft.com (personal accounts) or through your organisation's administrator.

5. Keeping and deleting data

• Removing an account in Settings deletes its local mail cache and its Keychain entry.
• Deleting the app's folder in ~/Library/Application Support/ByteMail removes all cached mail and drafts.
• Mail on your provider's servers is governed by your provider's own policy; bytemail only changes it when you ask it to (for example by deleting or moving a message).
• If you turn on "Send even when bytemail is closed", a small background item on your Mac delivers scheduled messages. It runs locally and can be turned off at any time in the app or in System Settings › Login Items.

6. This website

bytemailapp.com shows no advertising and loads no third-party fonts or images. It loads three third-party scripts: website analytics and affiliate referral tracking, both described next, and a spam check on the pre-order form, described below, which is not loaded unless you start using that form.

Website analytics. To see how many people visit and where they come from, the site uses DataFast. Its script records the pages you view, the referring site, your browser, operating system and device type, and an approximate location derived from your IP address, and it sets first-party cookies (datafast_visitor_id and datafast_session_id) to tell one visit from another. We use this only in aggregate, it is not used for advertising, and it is never connected to the bytemail app or to your mail (DataFast's privacy policy).

Affiliate referrals. Some people recommend bytemail through an affiliate link and earn a commission when someone they sent buys it. To know who sent whom, the site uses Affonso. Its script loads on every page. When you arrive through an affiliate link, it records the visit (the affiliate's link code, the referring site, your browser and an approximate location derived from your IP address) and sets first-party cookies (affonso_referral and affonso_data) that last 30 days. If you buy during that time, we pass the referral code, and nothing else about you, to Stripe with your order, and Affonso reads it there to credit the affiliate with the sale. If you didn't arrive through an affiliate link, nothing is recorded about you. It is not used for advertising and is never connected to the bytemail app or to your mail (Affonso's privacy policy).

The roadmap page. The roadmap shows our public roadmap from RoadmapAI in an embedded frame. Only that page loads it. Your browser fetches the frame, with its own styles, script and images, directly from RoadmapAI, which receives your IP address and browser details as any website does, and may set its own session cookies inside the frame. Nothing from this site is passed to it (RoadmapAI's privacy policy).

Like any web server, ours (a virtual server managed through Laravel Forge) processes your IP address, browser user-agent and the pages requested in order to deliver the site and protect it against abuse. These technical logs are kept for a short period — normally no longer than 30 days — and are not combined with anything else.

Pre-orders. If you pre-order, we store the email address you enter, which form you used and when, on that same server, together with the status of the order (started, paid or refunded), the amount and currency, and Stripe's reference numbers for the payment. We use the address to deliver bytemail to you and deal with your order. The payment itself happens on a checkout page run by Stripe, which, through Link, is the merchant of record: Stripe receives your email address from us and collects your name, billing address and payment details itself, under Stripe's privacy policy. We never receive your card details. If you start a pre-order and don't pay, the unpaid entry holds only your address. We may occasionally send it news about bytemail, such as a release or a change in price, and every such email has a one-click unsubscribe link. The entry is deleted on request. To keep bots out, the form uses Cloudflare Turnstile: when you click into the form, your browser loads Cloudflare's script, which checks — using your IP address and browser characteristics, without advertising cookies or cross-site tracking — that you are a person, and we ask Cloudflare to confirm the result (Cloudflare's privacy policy). Your address is not shared with anyone else, sold or added to any other list. Order records are kept as long as tax and accounting law requires. The site's admin area, used only by us, sets a sign-in cookie for us; visitors never receive one.

Purchases and licences. Every purchase — subscription or lifetime, including a pre-order — has a licence on our server: the email address it was bought with, the licence key, the plan and its status (for a subscription, the trial, renewal and cancellation dates Stripe tells us), Stripe's customer and subscription reference numbers, and, for each Mac you activate, the identifier, name, app version and last check time described in section 2. We use the address to send you your key, a sign-in code when you ask to restore a purchase and messages about your licence, and, occasionally, news about bytemail itself — what's new in a release. Every such update email has a one-click unsubscribe link, and unsubscribing never stops the emails about your licence. The address is never sold, shared for anyone else's marketing or added to any other list. Deactivating a Mac deletes its entry. Licence records are kept while the licence is in use and afterwards as long as tax and accounting law requires. Emails are sent through our mail delivery provider, Resend, which processes the address only to deliver them; we keep a record of which update emails went to which address so no one gets one twice, and of addresses that unsubscribed.

The earlier waitlist. Before pre-orders opened, the site had a waitlist. If you joined it, we still hold the email address you entered and when, and use it only to tell you that bytemail is available. It is deleted once that is done or as soon as you ask — write to hello@bytemailapp.com.

7. When you contact us

If you email us for support, we receive your address and whatever you choose to write, and keep the conversation for as long as needed to help you and to keep a record of it. Please do not send passwords or the contents of private mail.

8. Your rights

Because we do not hold your mail or account data, there is normally nothing for us to export, correct or erase — you control it directly on your Mac. For data we do hold (your purchase and licence records, your waitlist address, support correspondence, short-lived server logs) you may ask for access, correction, deletion or restriction, and you may object to processing, under the GDPR, UK GDPR, CCPA and similar laws. Write to hello@bytemailapp.com. You also have the right to complain to your local data-protection authority.

9. Children

bytemail is not directed at children under 13 (or the minimum age in your country), and we do not knowingly collect their data.

10. Security

Connections to mail providers use TLS. Credentials are kept in the macOS Keychain. Message HTML is displayed with scripts disabled. The app is signed with an Apple Developer ID and notarised by Apple. No system is perfectly secure; keeping macOS up to date and using FileVault protects the local mail cache.

11. Changes

If this policy changes, the new version is published on this page with a new date. Material changes to how the app handles your mail or Microsoft user data will also be shown in the app before they take effect.

12. Contact

Sergey Karakhanyan · hello@bytemailapp.com