Open-source email backup tools

6 email backup tools whose code is public under an OSI-approved license, rated for privacy with evidence. Picks first, then by score.

1. getmail6 Grade B

   Command-line mail retriever that downloads mail from POP3 and IMAP accounts into local Maildir or mbox files, or passes it to a delivery program. It is the Python 3 fork of getmail.

   GPL-2.0. Source code

2. Got Your Back Grade B

   Command-line tool that backs up and restores Gmail and Google Workspace mailboxes through the Gmail API, saving messages as local files with an index.

   Apache-2.0. Source code

3. imap-backup Grade B

   Command-line Ruby tool that backs up IMAP accounts to local files, with incremental updates, and can restore or migrate the backups to another IMAP server.

   MIT. Source code

4. ImportExportTools NG Grade B

   Thunderbird add-on that exports and imports messages and folders as EML, MBOX, HTML, PDF, plain text or CSV, and can back up the Thunderbird profile.

   GPL-3.0. Source code

5. isync Grade B

   Command-line tool, run as mbsync, that synchronizes IMAP mailboxes with local Maildir folders in both directions, including deletions and flag changes.

   GPL-2.0. Source code

6. OfflineIMAP Grade B

   Command-line tool that synchronizes IMAP mailboxes with local Maildir folders in both directions, so mail can be read offline and kept as a local copy.

   GPL-2.0. Source code

Compare all 10 email backup tools, open source or not.