A CTI Services Product

Own Your Inbox.
Keep Your Mail Server.

MailFlow is a self-hosted webmail and collaboration platform that plugs into the IMAP servers you already have. Self-learning spam protection, passkey login, shared calendars, notes, delegation — and a REST API for wiring up your own AI. One binary. Zero per-mailbox fees.

https://mail.yourcompany.com — Calendar
MailFlow calendar — shared calendars alongside your mail
1
Go Binary — Server, UI & Schema
Any
IMAP Server — Bring Your Existing Mail
$0
Per-Mailbox Fees. Ever.
100%
Self-Hosted. Your Data Stays Yours
What's Inside

Everything You Expect from Modern Email

🛡️

Self-Learning Spam Engine

A built-in scoring engine that learns from every message you mark. DNS-based checks and an adaptive filter mean the junk actually stops arriving — without sending your mail to a third-party scanner.

  • Bayesian-style learning from your corrections
  • DNS blocklists & SPF/DKIM/DMARC verification
  • Full transparency — see why every message scored
🔐

Passkey Security

Log in with WebAuthn passkeys — Face ID, Touch ID, Windows Hello, or a hardware key. No passwords to phish, no 2FA codes to intercept.

  • FIDO2 / WebAuthn native support
  • Hardware-backed authentication
  • Phishing-resistant by design
📅

Shared Calendars, Contacts & Notes

More than a mailbox. Share calendars across your team with attendees, invites, and reminders. A full contacts manager with labels. And notes with version history and sharing — so meeting context lives next to the meeting.

  • Shared calendars with attendee invites & reminders
  • Contacts with labels & grouping
  • Notes with version history and sharing
✉️

Works With Your Existing Mail Server

MailFlow doesn't replace your mail infrastructure — it makes it better. Point it at the IMAP server you already run (mailcow, Dovecot, Gmail, anything speaking IMAP) and it syncs bidirectionally: mail, folders, flags, all of it.

  • Two-way IMAP sync with instant push (IDLE)
  • Full mailbox backfill — history comes along
  • Keeps working alongside your current clients

Scheduled Send & Message Labels

Write now, send when it matters — schedule any message for the moment it should land, then reschedule or cancel before it goes. Organize the rest with Gmail-style labels, filters, and saved searches that run server-side.

  • Scheduled sending with reschedule & cancel
  • Color-coded labels — one message, many labels
  • Server-side filters & saved searches
👥

Delegation & Shared Access

Grant an assistant or teammate scoped access to your mailbox without handing over your credentials. Delegation is first-class, not an afterthought.

  • Scoped mailbox delegation
  • Multi-user with admin controls
  • Audit-friendly access model
📦

Own Your Data

Your mail lives in your MariaDB database on your server, with built-in backups and export tooling. Moving on from MailFlow? Take everything with you — standard formats, no lock-in.

  • Built-in scheduled backups
  • Standard export formats
  • Zero vendor lock-in

An API for Your Own AI Integrations

Every mailbox becomes a programmable surface. Generate an API key per user, then let the automations and AI agents you choose — your own models, your own prompts, your own rules — read calendars, query mail, and act on your behalf.

Unlike hosted suites, there's no vendor AI summarizing your correspondence by default. The only intelligence touching your mail is the intelligence you wire up yourself.

  • REST API with per-user API keys (Bearer or X-API-Key)
  • Calendar & mail endpoints, JSON in and out
  • Revocable keys with usage tracking
  • Agent-friendly: point any MCP client or script at it

Why Pay Rent on Your Own Communications?

Every message your business sends lives on someone else's server. Hosted suites charge per mailbox, scan your correspondence for their benefit, and can suspend you without notice. Compliance frameworks like SOC 2 and HIPAA make you document exactly where your data resides — "a vendor's cloud" is an increasingly uncomfortable answer.

MailFlow flips the model: one server you control, one database you own, unlimited mailboxes for your team. It's the difference between renting your business's memory and owning it.

"We built MailFlow for our own business first. It runs our email today — every feature on this page is production-tested, not roadmap vapor."

MailFlow vs. Hosted Suites

Unlimited mailboxes — no per-seat pricing
Data never leaves your server — no ad scanning
Compliance-friendly — you control retention & access
No account suspension because a bot flagged you
No surprise price hikes at renewal
No third-party AI reading your inbox
Simple, Flat Pricing

Pay Once. It's Yours.

Personal
$0
One mailbox, full power.
  • 1 account
  • All core features
  • Community support
Start Free
Small Business
$299 one-time
For tight teams.
  • Up to 10 users
  • 12 months of updates
  • Email support
Get Small Business
Business
$499 one-time
For growing companies.
  • Up to 50 users
  • 12 months of updates
  • Email support
Get Business

One-time license — MailFlow keeps running forever, even if you never renew. Renew for 40%/year to receive another 12 months of updates & support. Deployment, migration, and management services available separately.

Grab the Free Edition

The Personal tier is a real desktop app — a single binary that runs the whole MailFlow stack on your machine. No signup, no account, no limits on features.

Runs alongside your existing IMAP server. Apple Silicon & Intel · Windows 10/11.

Put Your Email Back in Your Hands

MailFlow is deployed and supported by CTI Services, LLC. We'll set it up on your infrastructure, migrate your existing mail, and stand behind it.

hello@ctiweb.io