📬⚡ ADHD IMAP Sync

ADHD IMAP Sync is a lightweight Alpine-based container that combines goimapnotify and fetchmail to instantly process incoming mail and deliver it to your local MDA (LMTP/SMTP, etc.).

The idea is simple: IMAP IDLE via goimapnotify detects new mail and immediately wakes up fetchmail to retrieve and deliver it locally. 📬⚡

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✨ Features

• 📨 Instant trigger on new messages (IMAP IDLE)
• 🛠️ Support for unlimited mail accounts
• 📂 Configuration via environment variables or Docker secrets
• 🔄 Auto-regenerated configs on container restart
• 🔐 Passwords via _FILE support
• 🛎️ Flexible delivery: LMTP (TCP/UNIX), SMTP, or custom commands

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🚀 Quick Start

Example compose.yml:

services:
  adhd-imap-sync:
    image: ghcr.io/kriakiku/adhd-imap-sync:latest
    container_name: adhd-imap-sync
    restart: unless-stopped
    secrets:
      - imap_work_pass
    volumes:
      - ./data:/config
    environment:
      TZ: UTC
      PUID: "1000"
      PGID: "1000"

      # Default settings
      ADHD_IMAP_HOST: "imap.example.com"
      ADHD_DELIVERY_TARGET: |
        mda "/usr/bin/maildrop -d %T"

      # Default account (no suffix)
      ADHD_IMAP_USER: "user@example.com"
      ADHD_IMAP_PASS: "SECRET1"
      
      # Extra account with "WORK" suffix 
      ADHD_IMAP_USER_WORK: "work@example.com"
      ADHD_IMAP_PASS_FILE_WORK: "/run/secrets/imap_work_pass"
      ADHD_DELIVERY_TARGET_WORK: |
        lmtp
        smtpname "work@target.com"
        smtphost /var/run/dovecot/lmtp
        # smtphost dovecot/24
secrets:
  imap_work_pass:
    file: ./imap_work_pass.txt

---

🔧 Environment Variables

Variable	Default	Description	Example
ADHD_IMAP_HOST	(none)	IMAP server hostname	imap.example.com
ADHD_IMAP_PORT	993	IMAP port	143
ADHD_IMAP_TLS	true	Use SSL/TLS for IMAP (true or false)	false
ADHD_IMAP_USER	(none)	IMAP username	user@example.com
ADHD_IMAP_PASS	(none)	IMAP password (or use _FILE)	secret
ADHD_IMAP_PASS_FILE	(none)	Path to file containing IMAP password	/run/secrets/imap_work_pass
ADHD_DELIVERY_TARGET	(none)	Fetch mail config part (LMTP/SMTP/MDA)	mda "/usr/bin/maildrop -d %T"
ADHD_POLL_INTERVAL	300	Fetchmail polling interval in seconds	60
ADHD_WAKE_MIN	3	Minimum delay in seconds between wake-up signals	5
ADHD_KEEP	keep	Whether to leave messages on the server (keep or no keep)	no keep

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Multiple Accounts

You can define multiple mail accounts by appending a suffix (e.g., _WORK, _ME, _GMAIL) to the variable names.
Each suffix will be treated as a separate account, with its own configuration.
If a variable is not set for a suffix, it will fall back to the default account values (without a suffix).

Account Name Generation:

• If suffix is empty → account name is "default".
• If suffix exists → account name is the suffix in lowercase (e.g., _WORK_UA → "work_ua").

Example with multiple accounts:

# Default account
ADHD_IMAP_HOST=imap.example.com
ADHD_IMAP_USER=user@example.com
ADHD_IMAP_PASS=secret

# Work account
ADHD_IMAP_HOST_WORK=imap.work.com
ADHD_IMAP_USER_WORK=me@work.com
ADHD_IMAP_PASS_FILE_WORK=/run/secrets/imap_work_pass

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📂 Configuration Files

Fetchmail stores the identifiers of processed messages in the file /config/.fetchids (used via the --idfile /config/.fetchids option).
This file ensures that already retrieved emails are not processed again after container restarts.
You can mount a persistent volume to /config to preserve this state:

volumes:
  - ./data:/config

You can provide a .netrc file for authentication either by mounting it as /config/.netrc.

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📦 How It Works

1. goimapnotify connects to IMAP and listens for new mail using IDLE.
2. When a new message arrives, it calls /usr/local/bin/fetchmail-wakeup.
3. fetchmail retrieves messages and delivers them to the configured ADHD_DELIVERY_TARGET.

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💡 Motivation

I run a self-hosted mail server (Stalwart) on my home server. But home servers aren’t exactly the most stable environment — in the last 3 years I had to move 5 times (thanks to one deranged dictator), and sometimes there are internet outages.

To keep my email reliable, I use MXroute for both sending and receiving. Stalwart lets me use external SMTP servers to send mail, but I couldn’t find a way to pull mail from external inboxes (would be hilarious if it actually exists 😅).

So, I turned to Fetchmail — but here’s the catch: it doesn’t support IMAP IDLE (push notifications for new mail). Instead, it just polls every few minutes. Not good enough — I want my OTP codes instantly ⚡📲.

That’s when I found GoIMAPNotify, which does support IMAP IDLE and can trigger commands when new mail arrives. Perfect match! So I built a Docker image that automatically generates configs for both tools and makes them work together.

Maybe someone else finds this handy too. 🙂

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📝 TODO

• Add tlsOptions support for goimapnotify:
  • unauthorized flag (allow self-signed certs)
  • starttls support
• Add per-account mailbox selection support (currently all mailboxes are monitored)