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Vaclav Kosar
Software And Machine Learning Blog

Easy Online Independence: 1. Mail Backup

This is first post of a series called "Easy Online Independence" aiming to provide cheap and easy way to increase your independence from current online service giants like Google and Facebook.

By independence I mean ability to at any time to stand alone or migrate to another service without major losses.

Mail Backup

Do you wonder what would happen if your mail provider decided to discontinue your service and delete all your mails? Paying or not for the service would you really have any way to restore your messages?

Fortunately there is an easy way to prevent these issues and stand more independently. Steps below are focused on Linux, but you should be able to do the same on other platforms.

mbsync (Post Update)

Based on a suggestion from a Redditor, I have migrated to this option and updated this post. These steps are based on Arch Linux Wiki and an older article GMail IMAP Backup With mbsync on Ubuntu.

  • Make sure you are using home folder encryption to avoid leaking your mail.
  • Create an special password only for mail backup. Google calls these passwords “app passwords”.
  • Install GPG2 (or plain gpg) to use as password manager: sudo apt-get install gpg2
  • Install mbsync (older name: isync): sudo apt-get install isync.
  • Generate key: gpg2 --quick-gen-key gmail
  • Create mail backup directory: mkdir ~/mbsync
  • Encrypt your password by typing it to console followed by enter after executing: read pass; echo $pass |gpg2 -e -r gmail -o ~/mbsync/gmail.gpg
  • Test password manager password-less decryption: gpg2 -q --for-your-eyes-only --no-tty -d ~/mbsync/gmail.gpg
  • Create mail directories: mkdir -p ~/mbsync/gmail/
  • Configure mbsync: vi ~/.mbsyncrc
    IMAPAccount gmail
    User <your username>
    PassCmd "gpg2 -q --for-your-eyes-only --no-tty -d ~/mbsync/gmail.gpg"

    IMAPStore gmail-remote
    Account gmail

    MaildirStore gmail-local
    Path ~/mbsync/gmail/
    Inbox ~/mbsync/gmail/Inbox

    Channel gmail
    Master :gmail-remote:
    Slave :gmail-local:
    # Exclude everything under the internal [Gmail] folder, except the interesting folders
    Patterns * ![Gmail]* "[Gmail]/Sent Mail" "[Gmail]/Starred" "[Gmail]/All Mail"
    Create Slave
    Sync PullNew
    SyncState *
  • Run first sync: mbsync gmail.
  • Configure incremental backups every 15 mins with extra logging:
    • crontab -e
    • 0,15,30,45 * * * * log="/home/vackosar/mbsync/gmail.log" && { echo "$(date) Starting" && mbsync gmail && echo "$(date) Exiting"; } 1>>"$log" 2>>"$log"


You can use Thunderbird:

  • To Avoid having to be logged into your service in your browser, which makes giant’s tracking easier.
  • For ability to use offline mail.
  • For provider agnostic gui

Win Alternative: IMAPSize Backup (Original Post)

This alternative uses a program running also on Windows. It however uses worse format for email “.eml” and doesn’t have other features.

  • Download IMAPSize win binaries.
  • Copy extracted imapsize into your home folder subdirectory mkdir ~/imapsize/.
  • Make sure you are using home folder encryption to avoid leaking data.
  • Install Wine: sudo apt-get install wine
  • Start and configure imapsize for your provider wine imapsize.exe. Gmail instructions can be found here.
  • Start first backup using imapsize gui.
  • Configure periodic incremental backups using cron:
    • crontab -e
    • 0 21 * * * cd ~/imapsize && wine imapsize -backup -account=gmail

05 Jul 2017

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