Mail and calendar for Linux and macOS. Gmail and IMAP accounts, Google Calendar, contacts, OpenPGP and S/MIME. GTK4 and libadwaita, written in Rust.
C-Rank Grade: B (Solid) - 62/100
External PR Merge Rate: 100%
Response Time: 2h
First Timer Success: 100%
c9dev/penguin-mail has a recorded first-timer success rate of 100.0%. Repositories ranked B typically provide actionable feedback during code reviews and actively nurture new community contributors.
Maintainers in c9dev/penguin-mail respond to incoming external pull requests in approximately 1.6 hours on average. Keeping PRs focused on single tasks and ensuring tests pass helps maintainers review faster.
The C-Rank™ system evaluates GitHub projects on a 0–100 scale using real data: PR merge rates, review turnaround time, active maintainer presence, and first-time contributor success. A score of 61.5 places c9dev/penguin-mail in the B tier.
The external contributor pull request merge rate for c9dev/penguin-mail is 100.0%, based on public PR activity from non-core contributors.
c9dev/penguin-mail currently has 4 active issue(s) tagged with beginner-friendly labels like "good first issue", "beginner", or "up-for-grabs".
Highly welcoming maintainers in c9dev/penguin-mail. Prompt code reviews with positive guidance for new contributors.
Discussions in c9dev/penguin-mail focus heavily on practical implementation feedback, code formatting standards, and issue reproduction details.
Unlinked PRs without issue context and changes that fail automated test suites face the highest review friction.
Average Response Latency
Tracks hours until a maintainer leaves a review, comment, or PR response.
External Acceptance Rate
Percentage of community pull requests successfully merged into main.
First PR Conversion
Rate at which developers submitting their first repository PR succeed.
Show contributors that your repository actively reviews and merges external pull requests.
[](https://getmerged.abhishekco.de/c9dev/penguin-mail?utm_source=github&utm_medium=badge)
Historical health & responsiveness evolution
External PR acceptance
First PR success rate
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90% receive response in
Maintainer review activity heatmap & prime window prediction
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Detected: UTC
Maintainers are most responsive around 12:00 UTC (12:00 UTC in your timezone). Recommended submission window is Tuesday - Thursday from 09:00 to 13:00 UTC (09:00 - 13:00 UTC local).
Maintainer Strategy: Maintainer Sweet Spot: PRs under 150 lines merge in ~4 hours (96% approval). Large PRs (>500 lines) take ~14 hours (45% approval). Keep your diff compact for rapid review.
What you are trying to do I would like to access to Exchange shared mailbox, shared with me, from my Outlook account. It works well with Outlook and Outlook Online, without any action from me, but they do not appear in Penguin-mail. What would help When adding an Outlook account, or when a new mailbox is shared with one of my account, the shared mailbox should appears as a new mailbox in Penguin Mail. What you do today No response Version penguin-mail 1.0.0
What you are trying to do It looks like very interesting application and I would like to use it both on LInux and macbook. What would help Checked with AI and it doesn't appear to be difficult to add macos support (biggest problem is webkitgtk-6.0, but can be handled via WKWebView for macos) and few things like tray (replaced with NSStatusItem). Main question is - I can try to use claude/codex to implement this support, but will you accept such MR? What you do today No response Version No response
What you are trying to do See calendars in Penguin Mail that don't belong to one of my mail accounts: for example a CalDAV calendar on a Nextcloud or Radicale server, an iCloud calendar, or a read-only ICS/webcal feed such as public holidays or a team schedule. Today a calendar only appears when it comes with a mail account: Google, Microsoft, or CalDAV on an IMAP/POP3 account "where the provider offers it". A calendar hosted anywhere else can't be added. What would help A way to add a calendar on its own, without setting up a mail account: CalDAV account: server URL, user name and password (or app password), with the same read and write support that account calendars have now. ICS/webcal subscription: a URL, read-only, refreshed on a schedule. Local calendar (nice to have): kept on this computer only. These would show in the calendar list and the Day/Week/Month/Agenda views alongside the account calendars, with their own name and colour, and be selectable as the target when creati
Version penguin-mail 1.0.0 How you installed it Other System Pop!_OS 24.04 LTS, X11 (cinnamon) Steps to reproduce Fresh start, installed from snap. Deb would have been preferred, but unfortunately the latest Pop! OS doesn't support it: penguin-mail : Depends: libadwaita-1-0 (>= 1.8~alpha) but 1.5.0-1ubuntu2 is to be installed Depends: libgtk-4-1 (>= 4.19.3) but 4.14.5+ds-0ubuntu0.10 is to be installed Recommends: gnome-shell-extension-appindicator but it is not going to be installed System is in dark mode. How often it happens It happened once Does it happen in the demo? Yes The message that triggers it No response What you expected Just me trying to test this out - looks good, just a couple of things making it hard to use What happened the font is not rendering correctly This means that the warning at the top of the window, about connecting password-manager-service, looks like it uses a full stop (.) instead of a colon (:). Can't see an option to set
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When evaluating whether to contribute to c9dev/penguin-mail, response velocity and maintainer engagement are crucial. GetMerged continuously tracks pull request trajectories, first-comment latency, and code review rounds to help developers avoid submitting pull requests to backlogged repositories.
Currently, maintainers of c9dev/penguin-mail acknowledge new external contributions in approximately 1 hours. Out of all submitted pull requests from non-core authors in the last 180-day window, 100.0% were successfully merged into the primary branch.
c9dev/penguin-mail has a recorded first-timer success rate of 100.0%. Repositories ranked Solid typically provide actionable feedback during code reviews and actively nurture new community contributors.
The initial maintainer response time averages ~1 hours. Keeping PRs scoped to single concerns and ensuring CI checks succeed will optimize review turnaround.
The C-Rank™ index scores repositories on a 0 to 100 scale using an objective formula: external PR merge rates, initial response speed, active maintainer count, and first-time contributor retention. A score of 61.5 places c9dev/penguin-mail in the Solid tier.
The external pull request merge rate is 100.0%. GetMerged isolates non-core community contributions so external developers get an accurate benchmark of PR acceptance probability.
Yes, c9dev/penguin-mail currently has 4 active issue(s) tagged with beginner-friendly labels. You can inspect these directly from the repository issues tab.
All metrics displayed for c9dev/penguin-mail are automatically retrieved via the public GitHub API and recalculated daily. Insider pull requests submitted by repository owners or organization members are excluded from merge rate calculations to preserve objective external contributor statistics.