email-backups-with-duplicati

script to create a full backup of multiple mail accounts and create encrypted backups using duplicati.

The mail backup is stored in the "Maildir" format. Many applications are supporting this format e.g. mutt

offlineimap is intentionally configured in "readonly" mode because we want to avoid any possible modification of our source data we want to backup...

usage:

• I highly recommend to read the bash scripts and understand them before you start. It is not very complicated. You should consider this as a template to create your own custom setup for mail backups
• check if the offlineimap configuration file meets your needs (simple IMAP should basically work out of the box. GMail might require some additional configuration)
  • extend to fit your needs. This documentation was useful for me:
    • https://www.offlineimap.org/resources/
    • https://wiki.archlinux.org/title/OfflineIMAP
• set credentials and mail configurations as necessary in secrets/pass_offlineimap.sh and secrets/pass_duplicati.sh
• modify scripts/collect_data_from_imap.sh (e.g. to work with multiple mail accounts)
• modify scripts/backup_data_using_duplicati.sh to use the right duplicati cli command to store your backup
  • in this case I used MEGA.nz as storage provider
  • How to create your own duplicati-cli command (how I did it but you can consult the official documentation asn well):
    • create duplicati backup job by web ui
    • export the backup command with password
  • Warning: if your $MEGA_USERNAME, $MEGA_PASSWORD, or $DUPLICATI_ENCRYPTION_PASSWORD contain a " it might cause problems for you (bash escaping and so on)
• run helper_download_data_and_create_backup.sh
• maybe create a cronjob to run this regularly

advanced usage:

• you can avoid the duplicati-cli repair step if you extend the docker command to mount a folder for the duplicati meta data (/config)
• Executing the "repair"-step has the advantage that this setup is kind of stateless (ignoring the pass.sh files for credentials). This has the disadvantage that if someone modifies / deletes your data you might not notice as easily.

warning:

• the passwords are stored in plaintext in the secrets/pass_*.sh files
  • I recommend to apply further security measures to avoid someone stealing all your valuable mail credentials

software requirements:

• docker
  • offlineimap and duplicati are running inside docker

tools used for this small project:

• docker
• offlineimap
  • the package is installed from the most recent fedora docker image -> it looks like the version you get installed is actually the offlineimap3 version (which is the official "successor" using python3 instead of python2)
  • fedora docker image: https://hub.docker.com/_/fedora
• duplicati
  • official duplicati docker image: https://hub.docker.com/r/duplicati/duplicati/

How to read Maildir files

• use mutt
• launch mutt with folders
  • mutt -f /data/Inbox
  • mutt -f /data/Sent

alternative use mbox format

• use this tool to convert Maildir format to convert to .mbox
  • https://github.com/bluebird75/maildir2mbox
• you can directly open the Mails using Gnome Evolution