126mail-cleanup（126 邮件清理）

126 Mail Cleanup

A step-by-step assistant for cleaning up, backing up, and optimizing your NetEase 126.com email account via IMAP. Designed to help reclaim cloud storage, reduce clutter, and create a reliable local archive.

Why Use This Skill

• Local backup: Download all emails and attachments to your machine — you own your data, not the cloud
• Cloud storage savings: 126 free accounts have limited space (typically 3-5GB); stripping large attachments can reclaim gigabytes, avoiding the need to pay for premium storage
• Inbox hygiene: Bulk-delete years of accumulated ads, subscriptions, and platform notifications while preserving important personal emails
• Safety first: Every destructive operation has a preview, confirmation, and backup step — nothing is permanently deleted without your approval

Commands

Setup — Step by Step

Step 1: Enable IMAP Access on 126.com

1. Log in to https://mail.126.com in a browser
2. Go to Settings (设置) > POP3/SMTP/IMAP
3. Enable IMAP/SMTP Service
4. Generate an Authorization Code (授权码) — this is NOT your login password
5. Save this code securely

Step 2: Configure the Skill

Provide your credentials when prompted:

MAIL126_ADDRESS=your_email@126.com
MAIL126_AUTH_CODE=your_authorization_code

Step 3: Verify Connection

Run /126mail setup to test the IMAP connection. The skill will:

• Connect to imap.126.com:993 (SSL)
• Send the required ID command (126 rejects clients without it)
• List all folders with email counts and total sizes

IMAP API Reference

126.com IMAP has several quirks. This skill handles them automatically, but here is the reference for transparency:

Connection Requirements

Folder Name Encoding (Modified UTF-7)

Chinese folder names are encoded. Common mappings:

Rate Limits

Critical Rule: Always Use UID, Never Sequence Numbers

This is the most important lesson. IMAP sequence numbers shift after any deletion. If you delete email #5, then email #6 becomes #5, #7 becomes #6, etc. Using sequence numbers after deletions WILL operate on wrong emails. Always use UID FETCH, UID STORE, UID COPY, UID SEARCH.

Phase 1: Local Backup (/126mail backup)

What It Does

• Downloads all emails (including attachments) from all folders
• Saves each email as message.eml with a _meta.json sidecar
• Organized as: backup_dir/folder_name/UID_subject/
• Supports resume on interruption — tracks progress in _download_progress.json

Batch Strategy

• Downloads in batches of 500 emails or 4GB (whichever comes first)
• Pauses between batches to avoid hitting 126's rate limit
• Reconnects every 20 emails to prevent timeout
• Socket timeout set to 300 seconds for large attachments

Key Decisions for User

Phase 2: Email Classification (/126mail classify)

What It Does

1. Fetches metadata (subject, from, to, date, size) for ALL emails via IMAP — no content download needed
2. Groups emails by sender domain
3. Classifies into categories:

- Platform/Ads: LinkedIn, Amazon, PayPal, JD, Taobao, etc. - Financial Notifications: Banks, brokers, payment services - Services: Cloud, SaaS, travel booking - Personal: Individual senders, known contacts

1. Outputs all_emails_meta.json (full index) and email_classification.json

Metadata-First Approach

• SEARCH and ENVELOPE operations are NOT rate-limited on 126
• Can index 40,000+ emails in minutes
• UID is tagged on every record for later operations

Key Decisions for User

Phase 3: Bulk Cleanup (/126mail cleanup)

What It Does

1. Shows classified email counts by category
2. User reviews and approves DELETE_DOMAINS list and KEEP_DOMAINS list
3. Safety net: Copies target emails to a staging folder (e.g., "广告邮件") BEFORE deleting from INBOX
4. Deletes from INBOX via UID STORE +FLAGS \Deleted + EXPUNGE
5. Random-sample verification (10 emails spot-checked)

The Safe Deletion Flow

INBOX emails  ──UID COPY──>  广告邮件夹 (staging copy)
     │
     └── UID STORE \Deleted + EXPUNGE (remove from INBOX)

User verifies in web client...

广告邮件夹  ──permanent delete──>  Gone (only after user confirms)

Key Decisions for User

Common DELETE_DOMAINS Reference

linkedin.com, crunchbase.com, amazon.com, jd.com, 
service.taobao.com, airbnb.com, booking.com, uber.com,
ctrip.com, trip.com, godaddy.com, coursera.org,
service.netease.com, insideapple.apple.com,
accounts.google.com, intl.paypal.com, citibank.com,
mail.meituan.com, sf-express.com, ...

Common KEEP_DOMAINS Reference

svb.com, gusto.com, berkeley.edu, alibaba-inc.com,
live.com, 139.com, pku.edu.cn, ...

Always let the user review and customize these lists based on their own email history.

Phase 4: Large Attachment Stripping (/126mail strip)

What It Does (Two-Phase Safety Process)

Phase A — Download Only (read-only, no server changes)

1. Search all folders for emails > threshold (default 50MB)
2. Download each email's attachments to local backup
3. Save metadata (_meta.json) for each
4. Track progress in _progress.json
5. Reconnect every 5 emails to avoid timeout

Phase B — Strip and Replace (destructive, requires explicit confirmation)

1. For each downloaded email:

- Fetch the full message with FLAGS and INTERNALDATE - Remove attachment parts from the MIME structure - Append a notice: [附件已移除 - 已备份到本地] with file list and original size - Upload the lightweight replacement (preserving original flags and date) - Delete the original heavy email

1. Track progress — resumable if interrupted

Storage Savings Example

Key Decisions for User

Error Handling

Progress Tracking

All operations save progress to JSON files:

• _download_progress.json — Full backup progress
• _progress.json — Large email strip progress
• cleanup_progress.md — Human-readable summary

This means every operation is resumable. If your connection drops, rate limit hits, or you close your laptop — just run the command again and it picks up where it left off.

Recommended Workflow

1. /126mail setup — Connect and verify
2. /126mail status — See current mailbox state
3. /126mail backup — Full local backup (run multiple times if rate-limited)
4. /126mail classify — Index and classify all emails
5. /126mail cleanup — Review and bulk-delete ads/subscriptions
6. /126mail strip — Reclaim space from large attachments
7. /126mail status — Verify results

Technical Notes

• Python 3.6+ with imaplib and email (standard library only, no pip dependencies)
• All IMAP operations use SSL (port 993)
• Modified UTF-7 encoding handled automatically for Chinese folder names
• ID command sent on every connection to satisfy 126's requirement
• All file names sanitized to remove illegal characters
• Duplicate attachment filenames handled with suffix numbering