Why we built Conduit Mail, an AI-powered email client

Conduit Mail is an AI-powered email client from Conduit Labs, in early access today. We built it because the client we wanted didn’t exist: one that looks and behaves like the mail apps we already knew, but where the AI sits inside the work instead of in a panel you forget to open. It started as one person’s inbox problem and stayed that specific.

That’s the short version. The longer version is six things annoying enough to build a mail client over, plus the things we decided not to build.

What was actually wrong with email?

Nothing, structurally. Email is fine. It’s federated, it’s open, and it outlived every replacement that was going to kill it.

We are not here to fix email. We’re here because the software people read email in stopped keeping up with the volume it delivers.

Here’s the list we started from. Each one is a real thing that happens on a Tuesday.

The 200-unread pile you triage by scrolling. Not reading. Scrolling, deciding, scrolling. Most of it is receipts, deploy notifications, and a newsletter you signed up for in 2021. The three messages that need a human are in there somewhere, and you find them by eye, every day, forever.

The reply you’ve been putting off for three days. It needs four sentences. You know all four. Opening the composer means committing to a tone, and by day three the reply also has to acknowledge that it’s been three days.

Filter syntax that predates the smartphone. Everyone knows filters would help. Most people give up after two or three, because building one means a dialog box with has:, from:, -in:, a size field in megabytes, and a checkbox whose behavior you have to test empirically. The mental model is fine. The interface is from another decade.

Search operators you can never remember. You know the email exists. You know roughly who sent it and roughly when. What you don’t know is whether it’s before:2026/01/01 or before:01/01/2026, so you type three words and scroll instead.

AI email tools that want your entire mailbox in their cloud. The pitch is usually good, and email is about as sensitive as personal data gets: password resets, medical appointments, legal threads, salary negotiations, the lot. We wanted a privacy page that says exactly what is stored.

An AI assistant that can’t see your email at all. If you work inside an AI assistant that already reads your code, your docs and your calendar, email is the one thing you still paste in by hand.

Six problems, six things to build. That’s the whole product plan.

Why we built Conduit Mail instead of using an existing client

We paid for most of them. Each one solves two of the six problems and leaves the other four to you.

To us, Superhuman is genuinely fast and its AI reads like it arrived later, bolted to the side. Shortwave goes deeper into AI than we needed. Gmail is free because you never left it. That’s our read as of September 2026, not a scorecard; our comparison posts will cite vendor pages with dates.

What none of them did was the specific combination we wanted: an interface familiar enough that there’s nothing to learn, AI woven through the parts that are tedious rather than parked in a sidebar, and mail that passes through our servers without being stored there.

So the honest answer to “why build another email client” is the least strategic one available. We wanted it for our own inbox and nobody was building it.

What does “familiar interface, unfamiliar power” mean in practice?

It means the first screen has no surprises in it. On a desktop screen: three panels — folders, message list, reading pane. Reply is a single keystroke. Nothing has been renamed to a verb.

You notice the second layer about an hour in, usually by accident.

• New mail gets sorted into six categories as it arrives, People, Notifications, Social, Newsletters, Promotions and Transactions, so the 200-unread pile is already six smaller piles. You can override any message’s category.
• ⌘K opens an assistant that can search your mail, summarize a thread, draft a reply and send it after you confirm, and work with your labels, notes and rules, showing each action it takes in a strip as it works.
• Search takes a sentence. “Attachments from Priya in July” becomes filter chips you can see and adjust. No operators: the sentence is interpreted by Claude, and the filters then run against mail already on your device. Nothing is indexed on our servers.
• Rules are described in English and compiled into real automations you can open, read, and edit like anything else.
• The composer will draft in your voice, rewrite a paragraph, or fix the grammar, so the four-sentence reply stops being a three-day project.
• Claude can connect to your mailbox through Conduit’s hosted MCP server (Plus and up), so the assistant you already work in can read, search, draft, and manage your mail without a copy-paste step.

That last one is the piece we’re least neutral about. It’s what we use most, and where the defaults mattered more than the feature.

The hosted MCP server lives at connect.conduitmail.app/mcp and speaks OAuth 2.1 with PKCE over Streamable HTTP, exposing 18 tools. Claude, whether that’s claude.ai, Claude Desktop, or Claude Code, is the client on the other end; it isn’t part of Conduit.

The defaults it ships with:

• Consent is granted per scope, and never widens on its own.
• A new connection defaults to drafts only.
• Direct sending is a separate opt-in with a daily cap, 50 by default.
• Permanent delete and moving mail between folders are withheld entirely; trash is allowed, and it is reversible.

Every call is audit-logged and visible per connected app in Settings → Integrations. Those defaults are why we were willing to build the connection at all.

What we decided not to build

A product story is mostly a list of refusals, so here are ours.

We didn’t invent a new inbox. No new metaphor, no re-education, no manifesto about how you’ve been doing email wrong. Every hour a user spends learning a paradigm is an hour the product cost them.

We didn’t make the AI autonomous by default. Summaries, drafts, search, and chat all wait for you to ask. One thing runs on its own: sorting new mail into the six categories.

A local classifier on your device does the sorting. On paid plans, the messages it’s unsure about get a second look, and just the sender, subject, and a short preview go to Anthropic, never the body. On the free plan, categorization stays entirely on your device and sends nothing.

We’ll also say the unflattering part out loud: that sorting is not consistent yet. A receipt lands in Notifications, a GitHub thread lands in People, and the pile you were trying to shrink gets a little weird. An overhaul is queued, starting with deterministic signals and using AI only for the mail that genuinely needs a judgment call.

We didn’t build a team product. No shared inboxes, no assignment, no comment threads. Team-inbox products do that job well, and it’s a different shape of software. Conduit is for one person’s mail.

We didn’t pretend the privacy story is simpler than it is. We don’t store your emails. We do store a few small things that make Conduit work the same on every device: your rules, the notes you save, and short writing samples from your sent mail so drafts sound like you everywhere.

All of it is visible in Settings, and all of it is yours to turn off or delete. Your email is never used to train AI models, by us or by Anthropic. The full accounting is on /security and /privacy.

Where the AI-powered email client stands today

Conduit Mail is in a private beta. It runs in the browser, nothing to install, and Gmail is the provider it’s built around: sign-in is Google-only. Yahoo, AOL, iCloud, Fastmail and generic IMAP connect too, over IMAP/SMTP rather than OAuth.

Conduit Labs is independent — no parent platform, no ad business, nothing behind the mail. Where the desktop and mobile apps stand is kept current on /download.

It’s free while the beta runs, and in-app billing isn’t open yet. When paid plans arrive, Free stays at $0 with five automation rules and Standard AI, Plus is planned at $9 a month and Pro at $27, both with unlimited rules and Smarter AI, and creating scheduled rules is a Pro feature, though scheduled execution isn’t wired up yet. If you’re the kind of person who ends up with a rule per sender, the five-rule ceiling on Free is the wall you’ll hit first. The plan detail is on /pricing.

Two things here are checkable rather than adjectives. Conduit Mail completed Google’s CASA Tier 2 security assessment, an independent review by TAC Security, a Google-authorized lab, and it’s verified by Google for restricted Gmail access.

Everything else here is a claim you should hold us to. The test we use internally is the least sophisticated one available: does the person who built it still want to open their own inbox in it. So far, yes.

Request early access at https://conduitmail.app — spots open in waves, Gmail, free while the beta runs. If you’d rather read the security page first, that’s the right instinct: /security.