Backup GMail (or other IMAP) accounts to disk

• Source Code
• API documentation
• Rubygem
• Continuous Integration

With versions above 2.x, this gems stores IMAP metadata in a backwardly-incompatible way. When upgrading, all old backups will be gradually deleted to allow for the new file format to be introduced.

$ gem install 'imap-backup'

In order to do backups, you need to add accounts via a menu-driven command line program:

Run:

$ imap-backup setup

By default, all folders are backed-up. You can override this by choosing specific folders.

setup creates the file ~/.imap-backup/config.json

E.g.:

{
  "accounts": [
    {
      "username": "[email protected]",
      "password": "secret",
      "local_path": "/path/to/backup/root",
      "folders":
        [
          {"name": "[Gmail]/All Mail"},
          {"name": "my_folder"}
        ]
    }
  ]
}

It connects to GMail by default, but you can also specify a server:

{
  "accounts": [
    {
      "username": "[email protected]",
      "password": "secret",
      "server": "my.imap.example.com",
      "local_path": "/path/to/backup/root",
      "folders":
        [
          {"name": "[Gmail]/All Mail"},
          {"name": "my_folder"}
        ]
    }
  ]
}

You can override the parameters passed to Net::IMAP with connection_options.

Specifically, if you are using a self-signed certificate and get SSL errors, e.g. certificate verify failed, you can choose to not verify the TLS connection:

{
  "accounts": [
    {
      "username": "[email protected]",
      "password": "secret",
      "server": "my.imap.example.com",
      "local_path": "/path/to/backup/root",
      "folders": [
        {"name": "[Gmail]/All Mail"},
        {"name": "my_folder"}
      ],
      "connection_options": {
        "ssl": {"verify_mode": 0},
        "port": 993
      }
    }
  ]
}

• Enable IMAP access to your account via the GMail interface (Settings/Forwarding and POP/IMAP),
• Under 'Sign-in & security', 'Signing in to Google', 'App passwords', generate a password for imap-backup,
• In imap-backup setup, set the server to imap.gmail.com

Note that email usernames and passwords are held in plain text in the configuration file.

The directory ~/.imap-backup, the configuration file and all backup directories have their access permissions set to only allow access by your user.

Manually, from the command line:

$ imap-backup

Alternatively, add it to your crontab.

Each folder is saved to an mbox file. Alongside each mbox is a file with extension '.imap', which lists the source IMAP UIDs to allow a full restore.

If you have problems:

1. ensure that you have the latest release,
2. turn on debugging output:

{
  "accounts":
  [
    ...
  ],
  "debug": true
}

All missing messages are pushed to the IMAP server. Existing messages are left unchanged.

This functionality requires that the IMAP server supports the UIDPLUS extension to IMAP4.

List IMAP folders:

$ imap-backup folders

Get statistics of emails to download per folder:

$ imap-backup status

• Secure - use a local file protected by permissions
• Restartable - calculate start point based on already downloaded messages
• Standalone - do not rely on an email client or MTA

• https://github.com/thefloweringash/gmail-imap-backup
• https://github.com/mleonhard/imapbackup
• https://github.com/rgrove/larch - copies between IMAP servers
• https://github.com/OfflineIMAP/offlineimap

Integration tests (feature specs) are run against a Docker image (antespi/docker-imap-devel:latest).

In one shell, run the Docker image:

docker run \
  --env [email protected] \
  --env MAIL_PASS=pass \
  --env MAILNAME=example.org \
  --publish 8993:993 \
  antespi/docker-imap-devel:latest

Currently, the integration tests with Docker are excluded from the CI run.

To run just the Docker-based tests:

rspec -t docker

To run all specs, including the integration tests, do the following:

rspec -O .rspec-all

1. Fork it
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Added some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create new Pull Request