feat: add Kagi Mail SMTP sending

[Microck]

what changed

adds kagi mail send for plain-text email using separate KAGI_MAIL_SMTP_USERNAME and KAGI_MAIL_SMTP_PASSWORD credentials. The transport requires certificate-verified STARTTLS. It does not reuse MCP OAuth tokens.

Also fixes Windows-only test issues found while validating on Yoga.

why

Kagi documents SMTP as a supported mail protocol. The exact SMTP credential and authentication contract is still unverified, so this PR is a draft and must not be merged until that is confirmed.

test plan

• cargo fmt -- --check on Yoga: passed
• cargo clippy --all-targets --all-features -- -D warnings on Yoga: passed
• cargo test --locked on Yoga: passed (221 unit, 89 integration, 15 mail CLI; 13 ignored)
• No human-run test or real SMTP authentication/send has been performed. No email was sent.

ai assistance disclosure

• agent_name: Hermes Agent and OMP
• agent_version: Hermes Agent v0.20.1; OMP 18.5.1
• model_used: gpt-6-luna and openai-codex/gpt-6.1-sol
• human_testing: No human-run testing. Automated checks were run by the AI agent on Yoga Windows ARM64. SMTP account authentication and real delivery were not tested.
• contribution_summary: Add an explicit SMTP send command with STARTTLS and isolated SMTP credentials, plus cross-platform test fixes.

This draft is not ready to merge until Kagi SMTP authentication is confirmed and a human tests the changes.

[vercel]

The latest updates on your projects. Learn more about Vercel for GitHub.

Project	Deployment	Actions	Updated
docs	Ready	Preview	Oct 6, 2026 6:04pm UTC

[coderabbitai]

Important

Draft PR not reviewed

Draft PRs are not automatically reviewed by default.

• Trigger a manual review

To automatically review draft PRs, update your CodeRabbit configuration:

reviews:
  auto_review:
    drafts: true

• Autopilot · Keep fixing CodeRabbit findings and required CI, and resolving merge conflicts

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands.}