git-send-email

git-send-email git-send-email is a command-line tool distributed with Git (software), designed to transmit patches and commits via SMTP mail for review, archival, or submission workflows. It integrates with mailing list-centric development models used by projects such as Linux kernel, Git (software), and GCC (GNU Compiler Collection), enabling automated message composition, threading, and metadata handling across diverse contributor environments like Debian, Fedora, and Red Hat.

Overview

git-send-email implements a bridge between the Git (software) object model and traditional electronic mail protocols such as SMTP and IMAP. It formats patches as RFC 5322-compliant messages, encodes commit metadata (author, committer, commit message) into headers compatible with review workflows used by Linux kernel maintainers, OpenBSD, and FreeBSD projects. The tool supports multiple authentication methods including SASL, STARTTLS, and certificate-based TLS common in Mozilla and Apache Software Foundation infrastructure. It is commonly scripted in automation systems like Jenkins (software), GitLab, and Buildbot to deliver patchsets to communities that rely on mailing lists such as LKML and project-specific lists at Gmane or Mailman-managed archives.

Usage

Typical invocation produces one or many patch emails from a commit range specified by Git (software) revision syntax, interacting with local repositories on platforms like GitHub, GitLab, and Bitbucket. Users can supply recipients including individual maintainers (e.g., Linus Torvalds, Greg Kroah-Hartman), project lists (e.g., LKML), or review addresses used by Patchwork (software). Command-line options control subject prefixes, cover letters, and threading headers aligned with Message-ID and In-Reply-To semantics used by mail clients such as Mutt, Thunderbird, and Microsoft Outlook. Integration points allow output to be inspected or piped into tools like procmail or sendmail alternatives on systems maintained by organizations such as Canonical (company) and SUSE.

Configuration

Configuration relies on Git (software) config entries and environment variables familiar to contributors to projects like Kernel.org and distributions like Arch Linux. Important settings include smtp.server, smtp.user, and smtp.encryption keys which mirror authentication approaches used by Gmail, ProtonMail, and institutional SMTP relays at universities and corporations. Identity settings (user.name, user.email) are drawn from Git (software) global and local configuration influenced by conventions at Linux Foundation-hosted projects and corporate codebases such as Google and Intel. Additional customization for aliases, cc lists, and per-repo behavior is frequently stored in dotfiles or project-specific configuration distributed through GitHub Gist or dotfiles repositories maintained by contributors like Linus Torvalds and other prominent maintainers.

Workflow Integration

In many open-source ecosystems—most notably Linux kernel, QEMU, GCC (GNU Compiler Collection), and Wireshark—git-send-email is a standard component of patch submission pipelines. It pairs with review trackers such as Patchwork (software), Maillist Archives, and patch-series viewers used by NGINX and Redis projects. Continuous integration systems like Travis CI, CircleCI, and GitLab CI/CD can invoke the tool to deliver test-result-linked patch emails, while code review processes at entities like OpenStack and GNOME rely on its ability to preserve commit metadata and threading for historic traceability. The tool also interoperates with patch formatting utilities employed by Kernel Janitors and static analysis platforms used in enterprises like IBM and Microsoft.

Troubleshooting and Tips

Common issues include authentication failures with SMTP relays hosted by Google, misconfigured TLS chains similar to problems reported against Let's Encrypt transitions, or malformed headers leading to spam filtering by providers such as Microsoft Office 365 and Yahoo! Mail. Remedies involve verifying configuration keys, testing connectivity with manual telnet sessions to SMTP ports, updating CA bundles used by distributions such as Debian and CentOS, and confirming that Message-IDs and References conform to standards from organizations like IETF. For reproducible results, users often create wrapper scripts and continuous integration jobs modeled after community examples from Linus Torvalds-led projects and public CI templates on GitHub. When dealing with threading or multipart diffs, aligning mail client expectations (e.g., Mutt and Alpine) and archiver heuristics in Mailman-managed lists resolves many delivery and display discrepancies.

Implementation and History

The tool originated as part of the growth of distributed version control practices embodied by Git (software) and the needs of projects such as Linux kernel to transmit patches by email; its design reflects conventions codified in RFCs overseen by the IETF. Over time, contributors from communities like Kernel.org and projects hosted on SourceForge and Savannah (software) extended its features to support modern authentication, threading, and MIME handling consistent with mail clients like Elm (email client) and infrastructure run by organizations including Debian and Red Hat. Its maintenance and integration have been influenced by key figures and teams active in the Git (software) ecosystem and by evolving standards from IETF working groups. Category: Category:Git (software)