Mail2NC

Polls an IMAP mailbox and uploads attachments to Nextcloud via WebDAV.

Quick Start

services:
  mail2nc:
    image: git.breis.ch/clement/mail2nc:latest
    environment:
      IMAP_HOST: mail.example.com
      IMAP_USER: scanner@example.com
      IMAP_PASS: secret
      NEXTCLOUD_URL: https://cloud.example.com
      NEXTCLOUD_USER: admin
      NEXTCLOUD_PASS: secret
    volumes:
      - mail2nc-data:/data

volumes:
  mail2nc-data:

For a production setup with Docker secrets and full security hardening, see examples/docker-compose.yml.

Environment Variables

Required

Variable	Description
IMAP_HOST	IMAP server hostname
IMAP_USER	IMAP login username
IMAP_PASS	IMAP login password
NEXTCLOUD_URL	Nextcloud base URL (e.g. https://cloud.example.com)
NEXTCLOUD_USER	Nextcloud username for WebDAV uploads
NEXTCLOUD_PASS	Nextcloud password or app token

Optional

Variable	Default	Description
IMAP_PORT	993	IMAP SSL port
IMAP_FOLDER	INBOX	IMAP folder to monitor
NEXTCLOUD_FOLDER	/Scans	Nextcloud destination folder
POLL_INTERVAL	30	Seconds between mailbox checks

Docker Secrets

All variables support the _FILE suffix for Docker secrets. When set, the value is read from the file path provided.

secrets:
  imap_password:
    file: ./secrets/imap_password.txt

services:
  mail2nc:
    environment:
      IMAP_PASS_FILE: /run/secrets/imap_password
    secrets:
      - imap_password

How It Works

1. Connects to the IMAP server over SSL
2. Searches for new/unseen emails
3. Extracts attachments from each email
4. Uploads them to Nextcloud via WebDAV with sanitized filenames
5. Marks successfully processed emails as read
6. Persists state to /data/state.json to survive restarts

Filenames follow the pattern: YYYYMMDD_HHMMSS_uid<N>_<original_name>

If an upload fails, the email is not marked as read and will be retried on the next poll.

Persistence

Mount a volume at /data to persist the processing state across container restarts. Without it, previously processed emails may be re-uploaded.