Switch to mailparser, UID watermarking, and 45s polling

- Replace hand-rolled MIME parsing with mailparser's simpleParser
- Use HTML body in prompts for better encoding/structure fidelity
- Replace IMAP IDLE (unreliable on Loopia) with 45s polling loop
- Track highest UID on startup; only fetch uid > last_uid each poll
  to avoid re-transferring old messages
- Add node: prefix to built-in imports

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

mail-buddy.mjs

@@ -1,9 +1,12 @@
 #!/usr/bin/env node
 import { ImapFlow } from 'imapflow';
-import { readFileSync } from 'fs';
-import { execFileSync } from 'child_process';
+import { simpleParser } from 'mailparser';
+import { readFileSync } from 'node:fs';
+import { execFileSync } from 'node:child_process';
+import { inspect } from 'node:util';
+import { setTimeout as sleep } from 'node:timers/promises';
 
-const CONFIG_PATH = process.env.MAIL_BUDDY_CONFIG ?? '/home/devilholk/.config/claude-mail-buddy/config.json';
+const CONFIG_PATH = process.env.MAIL_BUDDY_CONFIG ?? '/home/devilholk/.secrets/claude-mail-buddy.conf';
 
 function load_config() {
 	try {
@@ -15,17 +18,17 @@ function load_config() {
 }
 
 function make_prompt(message) {
-	const from = message.envelope.from?.[0]?.address ?? 'unknown';
-	const subject = message.envelope.subject ?? '(no subject)';
-	const body = message.text ?? '(no body)';
+	const from = message.from?.value?.[0]?.address ?? 'unknown';
+	const subject = message.subject ?? '(no subject)';
+	const body = message.html ?? message.text ?? '(no body)';
 
 	return [
-		`[mail-buddy] New email from ${from}`,
-		`Subject: ${subject}`,
+		`[mail-buddy] You have received an email from ${from} with the subject "${subject}".`,
+		`Reply using ccc according to MEMORY:email_protocol.md`,
 		``,
-		body.trim(),
-		``,
-		`Please reply to this email using the send-email CCC action, addressed to ${from} with an appropriate subject.`,
+		`--- Message body ---`,
+		body,
+		`--- End of message ---`,
 	].join('\n');
 }
 
@@ -39,29 +42,45 @@ function send_to_claude(text, config) {
 }
 
 async function handle_message(client, uid, config) {
-	const msg = await client.fetchOne(uid, { envelope: true, bodyStructure: true, source: true });
-	if (!msg) {
+	const raw = await client.fetchOne(uid, { source: true });
+	if (!raw?.source) {
 		return;
 	}
 
-	// Fetch plain text part
-	let text = '';
-	for await (const part of client.fetch(uid, { bodyParts: ['text/plain'] })) {
-		text = part.bodyParts?.get('text/plain')?.toString('utf8') ?? '';
-	}
-	msg.text = text;
+	const msg = await simpleParser(raw.source);
+	const sender = msg.from?.value?.[0]?.address ?? '';
 
-	const sender = msg.envelope.from?.[0]?.address ?? '';
 	if (!sender.toLowerCase().includes(config.allowed_sender.toLowerCase())) {
 		console.log(`Ignoring message from ${sender}`);
 		return;
 	}
 
-	console.log(`Dispatching message from ${sender}: ${msg.envelope.subject}`);
 	const prompt = make_prompt(msg);
 	send_to_claude(prompt, config);
 }
 
+async function process_new_messages(client, config, last_uid) {
+	const search = last_uid
+		? { uid: `${last_uid + 1}:*` }
+		: { unseen: true };
+
+	const uids = await client.search(search, { uid: true });
+	let new_last_uid = last_uid;
+
+	for (const uid of uids) {
+		if (uid <= last_uid) {
+			continue;
+		}
+		await handle_message(client, uid, config);
+		await client.messageFlagsAdd(uid, ['\\Seen'], { uid: true });
+		if (uid > new_last_uid) {
+			new_last_uid = uid;
+		}
+	}
+
+	return new_last_uid;
+}
+
 async function main() {
 	const config = load_config();
 
@@ -82,23 +101,17 @@ async function main() {
 	const lock = await client.getMailboxLock(config.imap.mailbox ?? 'INBOX');
 
 	try {
-		// Process any unseen messages already waiting
-		const unseen = await client.search({ unseen: true });
-		for (const uid of unseen) {
-			await handle_message(client, uid, config);
-		}
+		// Get highest existing UID without processing old messages
+		const all_uids = await client.search({ all: true }, { uid: true });
+		let last_uid = all_uids.length > 0 ? Math.max(...all_uids) : 0;
+		console.log(`Starting from UID ${last_uid}`);
 
-		console.log('Waiting for new mail (IDLE)...');
+		const POLL_INTERVAL = 45_000;
+		console.log(`Polling every ${POLL_INTERVAL / 1000}s...`);
 
-		// IDLE loop — re-enters IDLE after each notification
 		while (true) {
-			await client.idle();
-
-			const new_msgs = await client.search({ unseen: true });
-			for (const uid of new_msgs) {
-				await handle_message(client, uid, config);
-				await client.messageFlagsAdd(uid, ['\\Seen']);
-			}
+			await sleep(POLL_INTERVAL);
+			last_uid = await process_new_messages(client, config, last_uid);
 		}
 	} finally {
 		lock.release();

package.json

@@ -3,6 +3,7 @@
 	"version": "0.1.0",
 	"type": "module",
 	"dependencies": {
-		"imapflow": "^1.0.0"
+		"imapflow": "^1.0.0",
+		"mailparser": "^3.9.4"
 	}
 }