docker-compose.yml

version: '2.2'
services:
  # Generate self-signed certs
  # See: https://docker-mailserver.github.io/docker-mailserver/latest/config/security/ssl/#self-signed-certificates
  step-ca:
    image: smallstep/step-ca:latest
    working_dir: /certs
    volumes:
      - certs:/certs
    entrypoint:
      - /bin/sh
    user: 0:0
    command:
      - -c
      - |
          set -eu
          if [ ! -d demoCA ]; then
              mkdir -p demoCA

              step certificate create "Smallstep Root CA" "demoCA/cacert.pem" "demoCA/cakey.pem" \
                --no-password --insecure \
                --profile root-ca \
                --not-before "2021-01-01T00:00:00+00:00" \
                --not-after "2031-01-01T00:00:00+00:00" \
                --san "example.com" \
                --san "mail.example.com" \
                --kty RSA --size 2048

              step certificate create "Smallstep Leaf" mail.example.com-cert.pem mail.example.com-key.pem \
                --no-password --insecure \
                --profile leaf \
                --ca "demoCA/cacert.pem" \
                --ca-key "demoCA/cakey.pem" \
                --not-before "2021-01-01T00:00:00+00:00" \
                --not-after "2031-01-01T00:00:00+00:00" \
                --san "example.com" \
                --san "mail.example.com" \
                --kty RSA --size 2048
          fi

  # Mail server
  # See: https://docker-mailserver.github.io/docker-mailserver/latest
  docker-mailserver:
    image: docker.io/mailserver/docker-mailserver:12
    domainname: mail.example.com
    environment:
      - ENABLE_SPAMASSASSIN=0
      - ENABLE_CLAMAV=0
      - ENABLE_FAIL2BAN=0
      - ENABLE_POSTGREY=0
      - ENABLE_MANAGESIEVE=1
      - ONE_DIR=1
      - DMS_DEBUG=0
      - POSTFIX_INET_PROTOCOLS=ipv4
      - DOVECOT_INET_PROTOCOLS=ipv4
      - SSL_TYPE=manual
      - SSL_CERT_PATH=/certs/mail.example.com-cert.pem
      - SSL_KEY_PATH=/certs/mail.example.com-key.pem
    volumes:
      - certs:/certs
      - dms-mail-data:/var/mail
      - dms-mail-state:/var/mail-state
      - dms-mail-logs:/var/log/mail
      - dms-config:/tmp/docker-mailserver
    networks:
      default:
        aliases:
          - example.com
          - mail.example.com
          - imap.example.com
          - smtp.example.com
    depends_on:
      - step-ca

  snappymail:
    image: leojonathanoh/snappymail:pr-1
    ports:
      - 8888:8888
    volumes:
      - snappymail:/var/lib/snappymail
    networks:
      - default

  isync-imap-to-maildir:
    image: theohbrothers/docker-isync:1.4.4
    volumes:
      - mail:/mail
    networks:
      - default
    depends_on:
      - docker-mailserver
    stop_signal: SIGKILL
    entrypoint:
      - /bin/sh
    command:
      - -c
      - |
          set -eu

          while ! nc -w 1 -vz imap.example.com 993; do echo "Waiting for docker-mailserver to be up"; sleep 3; done

          echo "Getting self-signed certificate"
          mbsync-get-cert imap.example.com > /imap.example.com.pem

          echo "Creating /mbsyncrc"
          cat - > /mbsyncrc <<'EOF'
          IMAPStore example-remote
          Host imap.example.com
          User test@example.com
          Pass test
          AuthMechs LOGIN
          SSLType IMAPS
          # Trust our self-signed certificate(s). In production, this may not be needed.
          CertificateFile /imap.example.com.pem
          # Limit the number of simultaneous IMAP commands
          PipelineDepth 30

          MaildirStore example-local
          SubFolders Verbatim
          # The trailing '/' is important for Path
          Path /mail/
          Inbox /mail/INBOX

          Channel example
          Far :example-remote:
          Near :example-local:
          Patterns *
          Create Near
          Expunge Near
          SyncState *
          Sync Pull
          EOF

          echo "Sleeping forever"
          exec sleep infinity

  isync-maildir-to-imap:
    image: theohbrothers/docker-isync:1.4.4
    volumes:
      - mail2:/mail
    networks:
      - default
    depends_on:
      - docker-mailserver
    stop_signal: SIGKILL
    entrypoint:
      - /bin/sh
    command:
      - -c
      - |
          set -eu

          while ! nc -w 1 -vz imap.example.com 993; do echo "Waiting for docker-mailserver to be up"; sleep 3; done

          echo "Getting self-signed certificate"
          mbsync-get-cert imap.example.com > /imap.example.com.pem

          echo "Creating /mbsyncrc"
          cat - > /mbsyncrc <<'EOF'
          IMAPStore example-remote-2
          Host imap.example.com
          User test2@example.com
          Pass test
          AuthMechs LOGIN
          SSLType IMAPS
          # Trust our self-signed certificate(s). In production, this may not be needed.
          CertificateFile /imap.example.com.pem
          # Limit the number of simultaneous IMAP commands
          PipelineDepth 30

          MaildirStore example-local
          SubFolders Verbatim
          # The trailing '/' is important for Path
          Path /mail/
          Inbox /mail/INBOX

          Channel example
          Far :example-remote-2:
          Near :example-local:
          Patterns *
          Create Far
          Expunge Far
          SyncState *
          Sync Push
          EOF

          echo "Sleeping forever"
          exec sleep infinity

  isync-imap-to-imap:
    image: theohbrothers/docker-isync:1.4.4
    volumes:
      - mbsync:/mbsync # Sync state
    networks:
      - default
    depends_on:
      - docker-mailserver
    stop_signal: SIGKILL
    entrypoint:
      - /bin/sh
    command:
      - -c
      - |
          set -eu

          while ! nc -w 1 -vz imap.example.com 993; do echo "Waiting for docker-mailserver to be up"; sleep 3; done

          echo "Getting self-signed certificate"
          mbsync-get-cert imap.example.com > /imap.example.com.pem

          echo "Creating /mbsyncrc"
          cat - > /mbsyncrc <<'EOF'
          IMAPStore example-remote
          Host imap.example.com
          User test@example.com
          Pass test
          AuthMechs LOGIN
          SSLType IMAPS
          # Trust our self-signed certificate(s). In production, this may not be needed.
          CertificateFile /imap.example.com.pem
          # Limit the number of simultaneous IMAP commands
          PipelineDepth 30

          IMAPStore example-remote-3
          Host imap.example.com
          User test3@example.com
          Pass test
          AuthMechs LOGIN
          SSLType IMAPS
          # Trust our self-signed certificate(s). In production, this may not be needed.
          CertificateFile /imap.example.com.pem
          # Limit the number of simultaneous IMAP commands
          PipelineDepth 30

          Channel example
          Far :example-remote:
          Near :example-remote-3:
          Patterns *
          Create Near
          Expunge Near
          SyncState /mbsync/
          Sync Pull
          EOF

          echo "Sleeping forever"
          exec sleep infinity

networks:
  default:

volumes:
  certs:
  dms-mail-data:
  dms-mail-state:
  dms-mail-logs:
  dms-config:
  snappymail:
  mail:
  mail2:
  mbsync: