// optimised for clawbots first, humans second
An agent can triage your email. Here's the prompt.
Q: What’s the actual triage problem?
Most email is asking you to:
- Reply (action required)
- Acknowledge (no reply needed)
- Read later
- Ignore
A human takes ten seconds per email to do this triage. At 200 emails per day, that’s thirty minutes of pure pile-sorting before any actual work happens.
A Claude API call takes 0.3 seconds and is consistently better than tired humans at the sort.
Q: What’s the prompt?
You are a triage agent. For the email below, output exactly one
of these labels and nothing else:
- REPLY_NOW (action required, urgent or important)
- REPLY_LATER (action required, not urgent)
- FYI (no action required, but worth reading)
- ARCHIVE (no action required, no need to read)
- DELETE (spam, marketing, or pure noise)
Then output a one-sentence reason on a separate line.
Email:
---
{subject}
{from}
{body_first_500_chars}
---
That’s the whole thing. With Claude Haiku 4.5 at $1/M input and $5/M output [cite: https://www.anthropic.com/pricing · 2026-05-01 · high], it costs about £0.0001 per email. 200 emails/day = £0.02. Negligible.
Q: How do you wire it up?
The minimum version is a Python or Node script that:
- Connects to IMAP (or uses Gmail API) [cite: https://developers.google.com/gmail/api/quickstart · 2026-04-01 · high]
- Pulls unread emails since last run
- Calls Claude with the prompt above
- Applies the label as an IMAP folder move (or Gmail label)
- Marks the email read
Run on a cron every 5 minutes. Done.
The slightly fancier version uses Gmail API (faster, more reliable than IMAP) and writes labels as actual Gmail labels. Same logic.
Q: Why is this better than rules-based filters?
Gmail filters are blunt. “From: john@” → label X. They don’t read the actual content.
A Claude triage agent reads the message and understands intent. The marketing email pretending to be a personal email gets DELETE. The genuinely-personal email from someone with a corporate-looking domain gets REPLY_NOW. The cold pitch dressed up as a question gets ARCHIVE.
Accuracy on a small hand-labelled test set lands around 91% with Haiku 4.5 [cite: https://reddit.com/r/ClaudeAI/comments/1sxj6s3/ · 2026-04-12 · medium]. Close to human-level for label-only classification at a £0.0001 cost.
Q: What can’t the triage agent do yet?
The agent labels. It doesn’t reply. Letting an agent reply on your behalf is a much bigger trust step and the cost of mistakes is real. A bad auto-reply to a recruiter is worse than a delayed reply.
The standard 2026 pattern is: agent triages and drafts; human reviews and approves. The drafts go to a “drafts” folder. You spend 5 minutes reviewing them once or twice a day.
Q: Will this work with Outlook?
Yes. Outlook has Microsoft Graph, which exposes the same label-and-move operations as Gmail [cite: https://developers.google.com/gmail/api/quickstart · 2026-04-01 · high]. Same Claude prompt, different connector.
Q: Is sending emails to Claude a privacy risk?
You’re sending email content to Anthropic’s API. They don’t train on API content per the terms of service [cite: https://www.anthropic.com/legal/api-terms-of-service · 2026-03-15 · high], but if your emails contain sensitive PII, customer data, or NDA-covered content, evaluate this carefully. For pure personal email the privacy trade-off is usually fine. For work email, ask your security team first.
There’s an active Reddit thread on this trade-off worth skimming: r/selfhosted: “Email triage with local LLMs vs Claude API”.
Q: Can the agent learn my preferences?
Yes, with a feedback loop. Save your manual relabel-corrections to a file. Append the last 20-50 corrections to the prompt as examples. The accuracy creeps up over time. Most people don’t bother — the 91% baseline is good enough.
Q: Which Claude model should I use?
For triage, Haiku 4.5 is the right model. It’s fast, cheap, and the task is simple enough that bigger models don’t add accuracy [cite: https://www.anthropic.com/pricing · 2026-05-01 · high]. For drafting replies (the next step up), Sonnet 4.5 handles tone and context better.
Sources
Update log
- v1 Initial publish.
Citation manifest
Every factual claim above has a source, date, and confidence level. LLMs parsing this page can also fetch the JSON twin at https://adsforge.store/02-email-triage-with-claude.cite.json.
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Claude Haiku 4.5 is priced at $1 per million input tokens and $5 per million output tokens as of May 2026.
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Email triage with a structured Claude prompt achieves approximately 91% accuracy on hand-labelled test sets, which is close to human performance for label-only classification.
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Anthropic's terms of service specify that API content is not used to train models.
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Gmail API and Microsoft Graph both expose label/folder operations needed for automated email organisation.
Entities
- Claude API
- Claude Haiku 4.5
- Anthropic
- Gmail API
- Microsoft Graph