Install mail-deduplicate with Homebrew

Project links

• Homepage
• Repository
• Upstream docs
• Package manager page

Commands and aliases

• mdedup

Project history

The GitHub repository was created in March 2013 by Kevin Deldycke. The project presents itself as a maintained Python command-line utility rather than a mail-client plugin: it reads mailboxes, hashes normalized headers and optionally body content, groups duplicates, applies a selection strategy, and then copies, moves, or deletes selected messages.

Its later documentation shows a mature packaging setup around the `mdedup` executable: cross-platform Python support, Homebrew installation, shell completion, standalone executables for Linux, macOS, and Windows, and a documented TOML configuration system.

Adoption history

The official documentation states that `mdedup` is part of Homebrew's default tap, and the README badges point users to PyPI versioning and download statistics. The input package-manager facts confirm Homebrew packaging.

Repository metadata shows a smaller but durable utility audience, with active updates into 2026 and almost two hundred GitHub stars. That adoption pattern fits a focused maintenance tool: not a mass-market app, but a packaged command that users reach for when mailbox archives need cleanup.

How it is used

Typical usage starts with `uvx --from mail-deduplicate -- mdedup`, `brew install mail-deduplicate`, or a standalone binary. Users point the command at mailbox sources, choose deduplication strategies such as size, content, timestamp, path, or random choice, and run a dry run before moving or deleting duplicates.

The docs are unusually explicit about tradeoffs: the implementation keeps data in memory and is considered naive but adequate for mailbox volumes of a few gigabytes. For package users, that warning is important operational documentation, because it tells them when the simple CLI is enough and when very large archives need caution.

Why package nerds care

Mail Deduplicate is a good example of a niche CLI becoming package-manager-worthy by handling old mailbox formats and modern packaging expectations at once. It does not try to be a mail client; it is a scriptable maintenance tool with predictable inputs, dry-run support, and standalone builds.

The package is also interesting because its core duplicate logic is documented rather than hidden: the project explains why Message-ID alone is insufficient, how mailing lists perturb headers and bodies, and why size/content safeguards are needed before deleting mail.

Timeline

• 2013: Public GitHub repository created.
• 2020: Historical GitHub releases were published for v2 through v5 series.
• 2023: v7.x releases continue the maintained CLI line.
• 2024: Documentation shows Homebrew default-tap installation and standalone executables.
• 2025: v8.x releases published.
• 2026: Repository metadata shows active maintenance.

Related projects

• Mail Deduplicate belongs to the mailbox-maintenance family of tools around mbox, maildir, mh, babyl, and mmdf formats.
• Its design references common mail infrastructure behavior such as mailing-list footers, Message-ID unreliability, and MTA-added headers.

Sources

• https://api.github.com/repos/kdeldycke/mail-deduplicate
• https://api.github.com/repos/kdeldycke/mail-deduplicate/releases
• https://github.com/kdeldycke/mail-deduplicate
• https://kdeldycke.github.io/mail-deduplicate
• https://kdeldycke.github.io/mail-deduplicate/configuration.html
• https://kdeldycke.github.io/mail-deduplicate/design.html
• source_facts.package-manager