lfr
Your own mail server and newsletters in one Go binary on a $5 VPS, run by your coding agent from
the terminal. No admin UI, no per-subscriber bill.
curl -fsSL https://lfr.email/install.sh | sudo sh
On the server it goes to /usr/local/bin. Without sudo it installs to ~/.local/bin, which is enough
on a machine that only drives a server over ssh.
lfr runs mail for your domains from one binary on one small server: mailboxes, and newsletters with
their websites. An agent operates it through a CLI, on the server or over ssh; there is no admin UI, no
remote API and no monthly bill beyond the server (and a relay's cents per thousand mails where the
provider blocks port 25).
- A mail server: any
name@domain in seconds, aliases, catch-alls, plus-addressing, forwarding,
full-text search, replies, and a spam filter that learns from every message you move. DKIM (RSA and
Ed25519), SPF, DMARC, MTA-STS and TLS reporting for every domain; lfr domain add prints exactly the
DNS records to publish and lfr doctor checks them.
- Newsletters: lists with double opt-in and stored consent proof, a welcome issue, issues written in
Markdown with their images, checked before sending, rendered per reader with one-click unsubscribe
(RFC 8058) and unsubscribe by reply, click and reply counts, bounce and complaint handling that pauses
a list before it hurts your domains. Each list gets a fast website (issues, archive, feed, signup) on
its own host with HTTPS.
- A writing floor: every issue is held to its newsletter's brief and to rules against the habits of
generated prose, with an offline estimate of whether AI-text detectors would flag it. The rules and
the agent skills rest on built-in research (
lfr evidence): 136 reader and writer voices, 20
newsletters and 144 standards, studies and benchmarks, quoted verbatim.
Pure Go, SQLite, one process. About 25 MB of memory idle; comfortable on a 512 MB
droplet with dozens of domains.
Install
The script at the top installs the latest release for Linux and macOS, amd64 and arm64, after checking
it against the release checksums. With Homebrew: brew install anonyfox/tap/lfr. With Go 1.26 or newer: go install github.com/Anonyfox/lfr/cmd/lfr@latest.
1. A mail server
On the server (a DigitalOcean droplet named mail.example.com, for example):
sudo lfr setup --hostname mail.example.com --acme-email [email protected] --systemd
lfr domain add example.com # prints every DNS record to publish
lfr domain dns example.com --check # every record ok?
lfr doctor # reverse DNS, blocklists, outbound, certificates, disk, queue
setup creates /var/lib/lfr, a system user and a hardened systemd service allowed to bind ports 25, 80
and 443. On Cloudflare, set the records to "DNS only"; lfr domain dns example.com --zone prints them as
a zone file Cloudflare imports.
lfr delivers straight to recipients' mail servers when outbound port 25 is open. Many cloud providers
block it; DigitalOcean blocks ports 25, 465 and 587 on every droplet. Then lfr hands finished,
DKIM-signed messages to a relay on an alternate port for the last hop:
echo "$SES_SMTP_PASSWORD" | lfr relay smtps://[email protected]:2465 --spf include:amazonses.com
lfr relay # the route, a login test, and webhook URLs for the relay's bounce notifications
Amazon SES costs $0.10 to $0.16 per 1,000 messages; SMTP2GO has a free tier. See
operations for both.
2. Mailboxes
lfr mailbox add [email protected] --name "Example"
lfr mailbox alias [email protected] [email protected]
lfr mail ls --unread
lfr mail read 42
lfr mail reply 42 --md - <<< "Thanks, Ann. Feed it twice a day."
lfr mail mv 43 spam # teaches the spam filter
lfr events --follow # new mail, bounces, signups as they happen
3. Your agent
lfr skills install # setup, mailbox, research, concept, launch, issue, learn
export [email protected] # every command, from your laptop, over ssh
Every command accepts --json; exit codes are 0 (ok), 1 (failed), 2 (wrong usage or invalid input) and
3 (server not running). Human output ends with Next: and the step that usually follows.
SKILL.md is the entry point for agents.
4. A newsletter
The list lives on the server; the newsletter's editorial work lives in a project folder:
lfr list add bakers --name "Bakers Weekly" --from [email protected] --host news.example.com
lfr init bakers --list bakers --owner [email protected]
cd bakers && lfr check # names the next step and its skill, every time
lfr check walks a newsletter through research (readers' verbatim voices, peer newsletters), the brief
(concept.md: promise, cadence, format, length, subjects, voice, guardrails), the launch (lfr push
copies the promise, cadence and welcome issue to the list), and then every issue: plan, draft, fix,
test, approve, send, learn. Issues are Markdown files, with images next to them:
---
subject: Why your starter smells like nail polish
preheader: It is hungry, not dead, and two feeds fix it
idea: I001
---
# Your starter is hungry
It smells of acetone because it ran out of food. Feed it twice a day.
lfr issue put issues/acetone.md # create or update by slug, upload its images
lfr issue test acetone [email protected]
lfr issue send acetone --at 2026-10-23T07:00:00+02:00
lfr issue show acetone --learn # the learnings.md entry, two days later
Readers sign up at https://news.example.com/ (or any form that posts email to /subscribe),
confirm by clicking a button, and leave with one click. Published issues live at
/issues/<slug>. lfr site bakers --eject site copies the website templates into the project for editing and lfr push uploads them; lfr rules
lists every check with the research behind it.
Documentation
- Architecture: packages, data, the request paths.
- AGENTS.md: how to change things: a command, a migration, a rule, a skill.
- Operations: DNS, relays, deliverability, backups, upgrades, troubleshooting.
- Contributing: building, testing, fuzzing, releasing.
- The lfr.email Grok Bot: the handoff a Grok Bot follows to set up and share it.
MIT licensed.
