The homepage covers the three things nobody else can give you. This page is the rest — the full toolkit of a working email agent.
Four verdicts — important, learn from, not important, archive — applied by rules it learned from you, not filters you had to write.
Correct one call in plain words and it becomes a durable rule — exceptions included.
It remembers how you treat each sender and applies that knowledge only when that sender shows up.
Prospecting mail gets flagged and remembered. One click purges a sender for good.
Newsletters you never read get unsubscribed, not just archived.
Newsletters worth keeping are harvested into knowledge, then archived — read without reading.
Filed mail stays visible while its task is open, then archives itself when the work is done.
Email is work in disguise. Letterknife makes the work explicit.
Every real conversation is tracked as a task with status, history, and a next step.
Each task shows what is currently being asked of you — not just the last message.
Related threads roll up into goals, so pursuing one objective through three people is one item, not three.
It knows when someone replied, when they didn’t, and chases the silence for you.
Things others are driving get an eye icon and stay out of your plan until they need you.
See when something first came up versus when it last moved — nothing quietly rots.
The inbox turned into an operated day.
Calls, replies, approvals and chases assembled into one prioritized list, every day.
The plan shows how your hours split between calls and desk work before you commit to it.
Meetings sync in near-realtime — moved, cancelled, and declined calls resolve themselves.
A 24-hour digest of everything the agent did, so unattended never means unaccountable.
Drafts in your voice, sent only with your consent.
Replies are written from your history and style — ready before you open the thread.
Nothing sends without an explicit OK. Typed conversation never counts as permission.
It reads attachments for context and opens them natively with one click.
Drafts account for the whole conversation and the sender’s profile, not just the last message.
One brain across the places work actually happens.
Your login is your identity; connect every inbox you own under one plan — work, personal, side project.
Slack conversations flow into the same tasks and plan as email — one thread of truth per topic.
Every sender gets a profile: open tasks, history, disposition — visible right in the reader.
Sweep an entire backlog of senders in one run once the agent knows your preferences.
The onboarding is the training. No forms, no interview.
Resumable training slides: it judges, you correct, it converges — visibly, in one sitting.
“Usually skip — except my own community” is one correction, captured whole.
A running score of accepted recommendations shows the learning actually happening.
Everything it learned is plain text you can open, edit, or delete. No black box.
Most tools have an API about the product. Letterknife exposes the product itself to your AI.
Every capability — reading, tasks, calendar, sending — is a tool your own Claude can operate.
It budgets your Claude subscription like it budgets your time: visible spend, auto-pause, resume.
The agent, its memory, and its rules live on your machine. Close the lid and nothing of yours is anywhere else.
Being honest about what's not here yet:
The feature list is one thing. Watching it learn your mail in twenty minutes is another.