Resources
Two production-tested Claude Code skills for building a private AI email assistant on your own domain — no SaaS, no per-message fees, no vendor lock-in. MIT-licensed, free to use and modify.
Provision a custom-domain mailbox on Hostinger with full SPF / DKIM / DMARC authentication. Covers the gotchas that cause first-email-CC-filtered, attachments-flagged-as-spam, and Gmail spam folder problems. Includes a Node.js connectivity smoke test.
Use when: When you want a custom-domain mailbox (e.g. assistant@yourdomain.com) that actually delivers to inboxes.
Trigger keywords
Build an autonomous LLM-powered email reply loop on top of any IMAP/SMTP mailbox. Polls the inbox, loads a persistent agent context, calls Anthropic Claude with prompt caching, and either auto-sends the reply (allowlisted senders) or saves a draft for human review. Includes complete Node.js source, scheduling examples, cost projections, and a tuning guide.
Use when: When you want to delegate routine email triage and replies to an AI persona running on your own infrastructure.
Trigger keywords
Each skill is a folder containing a single SKILL.md file. To enable in Claude Code:
# Clone (or download zip from GitHub)
git clone https://github.com/ZealousDGTL/claude-email-skills.git
# Copy the folders into your Claude skills directory
cp -r claude-email-skills/hostinger-email-setup ~/.claude/skills/
cp -r claude-email-skills/ai-email-assistant ~/.claude/skills/Claude Code auto-discovers skills on next session start. Trigger them by mentioning any keyword from each skill's triggers: list.
The AI email assistant skill enforces Anthropic prompt caching by default. With caching:
| Volume | Monthly cost |
|---|---|
| 10 emails/day | ~$0.50 |
| 30 emails/day | ~$1.50 |
| 100 emails/day | ~$5 |
| 500 emails/day | ~$25 |
Without caching the same volumes are 5–10× more expensive. The skill includes the caching configuration so users don't have to remember.
Claude Code skills are markdown files placed in ~/.claude/skills/ that teach Claude how to perform specific tasks. When you mention a trigger keyword (e.g. 'set up email on hostinger'), Claude loads the skill's instructions as context and follows them. Skills make repeatable workflows reproducible across machines and teams.
Email automation built on top of SaaS tools costs $20–100/month per seat and locks you to one vendor. The same outcome built on a custom-domain mailbox plus the Anthropic API costs ~$1.50/month at typical volume. These two skills capture the production-tested workflow so anyone can build it without trial-and-error.
With Anthropic prompt caching (enforced by the skill's reference code), real-world cost is approximately $1.50/month at 30 emails/day, $5/month at 100 emails/day, $25/month at 500 emails/day. Without prompt caching, the same volumes cost 5–10× more — the skill includes the caching configuration by default.
Yes. The hostinger-email-setup skill is the example used in the documentation, but the ai-email-assistant skill works on top of any IMAP/SMTP provider — Google Workspace, Zoho, Fastmail, Migadu, Proton Bridge. Only the IMAP/SMTP host and port values change.
MIT License. Use freely, modify freely, ship in commercial products. Attribution appreciated but not required.
Clone the GitHub repository, then copy the skill folder into your ~/.claude/skills/ directory. Claude Code auto-discovers skills on session start. You can then invoke a skill by mentioning any of its trigger keywords (listed at the top of each SKILL.md file).
Open a pull request on the GitHub repository. Welcome contributions: adapter examples for Google Workspace OAuth, role-specific identity templates (sales, support, executive assistant), translations of the SKILL.md files into other languages, and additional providers. Open an issue first for larger changes so we can align scope.
MIT License. Use freely, modify freely, ship in commercial products. Attribution appreciated but not required.
Pull requests welcome on GitHub.