KT8 Mail Install now
100% open sourceSelf-hosted on Cloudflare

Professional email, calendar, and contacts—owned completely by you.

Everything you need from a modern email suite: calendar, contacts, team inboxes, rules, and privacy protection on your own domain. No monthly platform fees from KT8 Mail. Just run it natively on your Cloudflare account.

  • Every feature included out of the box
  • 10-minute automated setup
  • Your data and emails stay in your account

Organise with folders & labels

The KT8 Mail inbox, with emails tagged with coloured labels such as Work, Bills, Family and Travel, and shared inboxes in the sidebar
KT8 Mail on an iPhone, showing the inbox

Screenshots of KT8 Mail. Names and messages are examples.

Built for teams, families and businesses

One install. All your domains, people and inboxes.

  • Multiple domains

    Host multiple domains on a single KT8 Mail install. Manage them easily from the admin page.

  • Users & aliases

    Up to 50 personal mailboxes, plus shared mailboxes and as many aliases as you need.

  • Shared mailboxes

    One inbox. Zero mixed messages. Effortlessly manage sales@, support@ or hello@ as a team. Unlimited shared mailboxes.

  • Shared calendarsComing soon

    Team and family calendars you can share, view and edit together.

  • Super-fast webmail

    Runs on Cloudflare’s global network, served by a data centre near you.

  • 17Features includedNo tiered paywalls or artificial limits
  • £0Software costFree and open source forever
  • 50Personal mailboxesPlus shared mailboxes, all on one $5 Cloudflare plan
  • 100%Owned by youYour domain, your Cloudflare account, your data

KT8 Mail charges no software fees. Outbound email uses Cloudflare’s Workers Paid plan ($5 a month paid directly to Cloudflare for your entire organisation, not per user). Inbound email routing is completely free.

What you get

Complete control over your communications. Zero feature restrictions.

Get every feature, security update, and enhancement without enterprise upsells.

New

Calendar & reminders

Manage your schedule right alongside your inbox with month, week, day and list views. Drag and drop to create or reschedule events, customise colours, set repeat rules and receive push reminders on your phone and Mac. Private events automatically display as Busy to others.

  • Colour-coded calendars for personal, work, and team schedules
  • Flexible recurring rules (daily, weekly, monthly, annual)
  • Unified access: Mail, Calendar, and Contacts just one tap away
The calendar in month view, with colour-coded events and a half-term holiday across a week The calendar's list view on an iPhone

Team Access & Shared Inboxes

Invite colleagues or family to sign in with their own email address and open only the mailboxes you give them. Shared inboxes like sales@ sit in everyone's sidebar, and each reply shows who sent it.

  • Up to 50 personal mailboxes, plus shared ones, with no per-mailbox fees
  • Shared mailboxes for sales@, support@, or family accounts
  • Passwordless authentication via Cloudflare Access
The shared Sales inbox in the KT8 Mail sidebar The Users page, listing who can sign in and which mailboxes each person opens
Works anywhere

Native experience across Windows PC, Mac, iOS, and Android.

Access your communications from any modern browser on desktop, tablet, or mobile. Pin KT8 Mail to your Windows PC taskbar, Mac Dock, iOS home screen, or Android app drawer with full push notifications and unread badge counts.

Works anywhereProgressive Web App (PWA)

Reading an email on an iPhone The inbox on an iPhone, with a round Compose button The calendar on an iPhone
Built for performance & privacy

Enterprise-grade capabilities on your own domain.

Inbox rules

Sort new mail as it arrives. Choose who it's from, who it was sent to, or words in the subject or message, then move it to a folder, add labels, mark it as read or star it.

Inbox rules in Settings: Bills, Receipts, Family and Newsletters

Built-in spam filter

Automated analysis filters out phishing attempts, spoofed senders, and junk mail. Quarantined emails clearly explain why they were flagged in plain language.

A fake PayPal email in Spam, with the reasons it was moved there

Privacy protection

Block hidden trackers so senders can't tell when or where you opened their email.

A newsletter with a note: Blocked 3 trackers from Mailchimp, Google and others

Multiple addresses & catch-all

Manage aliases like hello@ or support@ from a single inbox. KT8 Mail automatically selects the correct reply-from address for incoming mail, while catch-all routing prevents misaddressed emails from bouncing.

Extra addresses support@ and invoices@ in Settings, with the Reply from choice

Multiple inboxes

Configure and manage unlimited mailboxes and custom domain aliases from a single dashboard.

The Mailboxes page, with mailboxes on two domains

Backup & export

Nightly backups of all your mail, a one-click download, and an easy way to bring your old mail across from Gmail, Apple Mail or Thunderbird.

Backup and export settings, with nightly backups switched on

Organise with folders & labels

Organise rapidly using folders and labels. Right-click on desktop or press and hold on mobile to reply, label, archive, or move messages without opening them.

The right-click menu on an email: Reply, Forward, Archive, Move to, Label as and more
Every feature

All 17 features included out of the box.

  • Custom email addressSend and receive emails using your own website domain (e.g. name@yourdomain.co.uk).
  • Calendar & remindersManage your schedule right alongside your inbox with month, week, day and list views. Drag and drop to create or reschedule events, customise colours, set repeat rules and receive push reminders on your phone and Mac. Private events automatically display as Busy to others.
  • Team Access & Shared InboxesInvite colleagues or family to sign in with their own email address and open only the mailboxes you give them. Shared inboxes like sales@ sit in everyone's sidebar, and each reply shows who sent it.
  • Organise with folders & labelsCategorise messages using folders or Gmail-style labels, search your inbox instantly, and save drafts for later.
  • Inbox rulesAutomatically process incoming mail: route it to folders, assign labels, mark it as read, or star messages instantly.
  • Built-in spam filterKeep your inbox clean with automated scam detection, a clear reason for every email in Spam, and one-click sender blocking.
  • Privacy protectionBlock hidden trackers so senders can't tell when or where you opened their email.
  • Large file sharingSend attachments up to 3.5 MB directly, or securely share files up to 95 MB via download links, with optional password protection.
  • Automated replies & templatesSet up email signatures, reusable templates, and scheduled out-of-office responses.
  • Smart address bookManage your contacts with automatic address suggestions as you type.
  • Multiple inboxesSet up and manage as many mailboxes as you need, across all of your domains.
  • Multiple addresses & catch-allManage aliases like hello@ or support@ from a single inbox. KT8 Mail automatically selects the correct reply-from address for incoming mail, while catch-all routing prevents misaddressed emails from bouncing.
  • Backup & exportNightly backups of all your mail, a one-click download, and an easy way to bring your old mail across from Gmail, Apple Mail or Thunderbird.
  • Works anywhereAccess your email on any web browser, whether you're on a computer, tablet, or phone.
  • Progressive Web App (PWA)Add KT8 Mail to your Windows PC taskbar, Mac Dock, or iPhone or Android home screen. Supports push notifications for new emails and dynamic unread badge counters.
  • Optional AI reply assistantDraft quick responses automatically whenever you choose to turn it on in Settings.
  • Hassle-free updatesKeep your email system up to date with a single click via the KT8 Installer.

Coming soon

  • Calendar sharingTeam calendar sharing, and see your calendars in Apple Calendar, Outlook and Google Calendar.
  • Email ForwardingAutomatically pass on incoming emails to another address, such as your old Gmail or a colleague, while keeping a copy in your inbox.
  • File StorageKeep your documents and photos in private online storage on your own Cloudflare account, ready to attach to any email.
  • NotesJot down ideas, lists and reminders, and keep them private alongside your email.
Demo

See KT8 Mail in action (1-minute overview).

Calendar, team inboxes, inbox rules, spam filtering, multiple domains, and all 17 features.

Sound on for the music. The Cloudflare sign-in is an example screen.

How it works

Free, open-source software—running on your own Cloudflare account.

You only pay the $5 a month to Cloudflare.

The app

KT8 Mail

Free

KT8 will never charge you. Every feature is included.

Read why →
Where it runs

Hosted on Cloudflare

$5a month, paid to Cloudflare

Your mail lives in your own Cloudflare account. Just receiving? That part is free.

What's Cloudflare? →
Setting it up

One-click install

  1. 1
  2. 2
  3. 3
  4. 4

Sign in with Cloudflare, pick your domain, and the installer does the rest.

See the steps →
How to install

Easy steps to set up your very own email solution.

  1. 1Create a Cloudflare accountIt's free. Show me how
  2. 2Get a domainBuy one like yourname.co.uk for about £10 a year, or move yours across. Show me how
  3. 3Turn on the $5 planThis enables outbound email. Just trying it? Skip this for now. Watch how (21 seconds)
  4. 4Press Install nowSign in with Cloudflare. No GitHub account needed.
  5. 5Pick your domainThe installer sets up your inbox, your web address and your email records.
  6. 6Open your inboxSign in at mail.yourname.co.uk and start sending and receiving.
Install now

Updating later is the same: run the installer again, and your mail and settings are kept.

Free, and always will be

Everyone's a Pro.

There are no paid tiers, no locked features, and no premium editions. You get everything you see today, and every feature, upgrade and security fix released in the future, completely free of charge.

Up to 50

personal mailboxes included

$5 a month for your whole organisation, not per person. Secure passwordless sign-in via Cloudflare Zero Trust is completely free for up to 50 user accounts, with shared mailboxes (like sales@ or support@) and email aliases included at no extra cost.

Illustration of Paul O'Brien
An introduction from the founder

Why I built KT8 Mail

I've spent over twenty years in tech, software development and corporate resilience, always keeping a close eye on email infrastructure and cyber security. In that time I've hopped between almost every email provider on the market (Fastmail was my long-time favourite), and I always joked about building my own to get everything just right.

When Cloudflare introduced Email Sending alongside its open-source Agentic Inbox project, I saw the chance to turn that running joke into reality.

Read the rest

In a matter of days, I turned a basic prototype into KT8 Mail: a complete webmail app hosted on Cloudflare for just $5 a month. I packed it with the features I need every day: Team Access & Shared Inboxes, Multiple addresses & catch-all, Large file sharing with encrypted download links, Organise with folders & labels, Automated replies & templates, and Backup & export.

Rather than turn it into another paid subscription service, I've made KT8 Mail completely free and open source. Every feature, update and security fix is free for everyone, with no tracking, no adverts and no lock-in. (If it leads to the occasional custom development project for my consultancy, that's a great bonus.)

Install your free copy today, and join our community forum to share feature requests and chat about the future of the app.

Best,

Paul O'Brien

Founder, KT8 Mail · paulobrien.com

Also from me: ReaderCount, private website stats for bloggers. No cookies, no cookie banner.

Who it's for

Made for everyone.

  • BusinessesShared inboxes like sales@ and help@, and large files sent as protected download links.
  • ClubsOne address like secretary@ that passes from volunteer to volunteer.
  • SolopreneursA professional address on your own name, for $5 a month.
  • FamiliesOne family domain, with a mailbox for each person.
  • IndividualsYour own address, your own inbox, and nobody else's adverts.
Privacy

No lock-in. Forever yours.

You own your data. No tracking pixels, no adverts, no snooping. Export everything whenever you like, as a standard file any mail app can open.

What can we see?

Nothing. Our installer only has access while it sets things up, then hands its permission back. Your mail, contacts and settings live in your Cloudflare account, not ours. Our privacy notice →

What can Cloudflare see?

Cloudflare runs the servers your mail is stored on, under your own account. Like every email service, it keeps a delivery log of who sent mail to whom, for up to 30 days. Cloudflare's privacy policy →

Every line of KT8 Mail is open, so anyone can check what it does. Read the code on GitHub →

We believe everyone should own their own email.

Install KT8 Mail on your own Cloudflare account in about ten minutes. It's free.

Not ready yet? Leave your email address for the occasional update. We only keep your address and the date, and you can ask us to delete it at any time.

KT8 Mail is kept free by sponsors and by setup and custom work. Questions? Read the common questions.