Email Operations Skill

Overview

This skill provides email capabilities through direct IMAP/SMTP protocol access using curl. It supports:

• Sending emails via SMTP with TLS
• Fetching email lists via IMAP
• Reading email content by ID
• Multi-account support with secure credential storage

Architecture

• Protocol: Direct IMAP (port 993) and SMTP (port 465) over TLS
• Security: Passwords stored in macOS Keychain, never in config files
• Compatibility: Uses curl with OpenSSL/LibreSSL (better Tencent Enterprise Mail support than rustls)
• Configuration: YAML-based account management in references/accounts.yaml

Available Scripts

1. Send Email (send-email.sh)

Send emails via SMTP with support for inline or file-based content.

Usage:

./scripts/send-email.sh -t recipient@example.com -s "Subject" -b "Message"
./scripts/send-email.sh -t recipient@example.com -s "Subject" -f message.txt
./scripts/send-email.sh -t recipient@example.com -c another@example.com -s "Subject" -b "Message"

Parameters:

• -a ACCOUNT - Account name (default: from accounts.yaml)
• -t EMAIL - Recipient email (required)
• -c EMAIL - CC recipient (optional)
• -s TEXT - Email subject (required)
• -b TEXT - Email body inline (required if no -f)
• -f FILE - Email body from file (required if no -b)

2. Fetch Emails (fetch-emails.sh)

Retrieve email headers from a mailbox.

Usage:

./scripts/fetch-emails.sh                    # Fetch 10 latest from INBOX
./scripts/fetch-emails.sh -n 20              # Fetch 20 latest
./scripts/fetch-emails.sh -m "Sent"          # Fetch from Sent folder

Parameters:

• -a ACCOUNT - Account name (default: from accounts.yaml)
• -m FOLDER - Mailbox folder (default: INBOX)
• -n N - Number of emails to fetch (default: 10)

3. Read Email (read-email.sh)

Read full content of a specific email by ID.

Usage:

./scripts/read-email.sh 123                   # Read full email
./scripts/read-email.sh -p HEADER 123         # Headers only
./scripts/read-email.sh -p BODY 123           # Body only

Parameters:

• -a ACCOUNT - Account name (default: from accounts.yaml)
• -m FOLDER - Mailbox folder (default: INBOX)
• -p PART - Part to retrieve: HEADER, BODY, or TEXT (default: TEXT)
• EMAIL_ID - Email ID (required, positional argument)

Configuration

Account Setup

Edit references/accounts.yaml to add email accounts:

default_account: SUSTech

accounts:
  SUSTech:
    email: qihr2022@mail.sustech.edu.cn
    display_name: Hanrui Qi
    imap:
      host: imap.exmail.qq.com
      port: 993
      login: qihr2022@mail.sustech.edu.cn
      protocol: imaps
    smtp:
      host: smtp.exmail.qq.com
      port: 465
      login: qihr2022@mail.sustech.edu.cn
      protocol: smtps

Password Management

Passwords are stored in macOS Keychain. Set them using:

# IMAP password
security add-generic-password \
  -a "qihr2022@mail.sustech.edu.cn" \
  -s "email-imap-sustech" \
  -w "your-password" \
  -U

# SMTP password
security add-generic-password \
  -a "qihr2022@mail.sustech.edu.cn" \
  -s "email-smtp-sustech" \
  -w "your-password" \
  -U

Keychain service naming convention:

• IMAP: email-imap-{account_name_lowercase}
• SMTP: email-smtp-{account_name_lowercase}

Common Use Cases

1. Send a Quick Email

When user says: "Send an email to alice@example.com about the meeting"

cd /Users/seven/Claude/.claude/skills/email
./scripts/send-email.sh \
  -t alice@example.com \
  -s "Meeting Discussion" \
  -b "Hi Alice, I wanted to follow up on our meeting..."

2. Check Recent Emails

When user says: "Check my email" or "Any new emails?"

cd /Users/seven/Claude/.claude/skills/email
./scripts/fetch-emails.sh -n 5

Parse the output and summarize for the user.

Search / Filter (Pipe + grep/rg)

This is a lightweight way to "search" within the recent emails that fetch-emails.sh fetched (headers only: From/Subject/Date).

cd /Users/seven/Claude/.claude/skills/email

# 任意关键字（例如 github），同时保留邮件 ID 行（便于后续 read）
./scripts/fetch-emails.sh -n 200 | rg -i "github" -B 2

# 主题关键字（建议用 rg；没有 rg 就用 grep -E）
./scripts/fetch-emails.sh -n 200 | rg "主题:.*会议" -B 2
./scripts/fetch-emails.sh -n 200 | grep -E "主题:.*会议" -B 2

# 发件人关键字
./scripts/fetch-emails.sh -n 200 | rg "发件人:.*alice" -B 1

# 提取匹配到的邮件 ID，然后读取正文（取第一个匹配）
email_id="$(
  ./scripts/fetch-emails.sh -n 200 |
    rg -i "github" -B 2 |
    sed -nE 's/.*邮件 #([0-9]+).*/\1/p' |
    head -n 1
)"
./scripts/read-email.sh "$email_id"

If email_id is empty, increase -n (fetch more recent emails) or adjust the keyword/regex.

3. Read Specific Email

When user says: "Read email #3" or "Show me the latest email"

cd /Users/seven/Claude/.claude/skills/email
./scripts/read-email.sh 3

4. Email Automation

Combine with other skills for automation:

• Check calendar → Send reminder emails
• Monitor inbox → Create system notifications
• Fetch emails → Parse and extract information

Error Handling

Common Issues

1. Authentication Failed

   • Verify Keychain passwords are set correctly
   • Check if IMAP/SMTP is enabled in email provider settings
   • For Tencent Enterprise Mail, use app-specific password

2. Connection Timeout

   • Verify network connectivity
   • Check firewall settings for ports 993 (IMAP) and 465 (SMTP)
   • Confirm host and port in accounts.yaml

3. TLS Handshake Failed

   • This skill uses curl with OpenSSL/LibreSSL for better compatibility
   • If issues persist, check email provider's TLS requirements

Security Considerations

• Never log or display passwords - they're in Keychain only
• Confirm before sending - especially for important emails
• Validate recipients - check email addresses before sending
• Respect privacy - don't read emails unless explicitly requested

Provider-Specific Notes

Tencent Enterprise Mail (exmail.qq.com)

• IMAP: imap.exmail.qq.com:993 (SSL/TLS)
• SMTP: smtp.exmail.qq.com:465 (SSL/TLS)
• Requires IMAP/SMTP enabled in settings
• Recommend using app-specific password
• Note: IMAP SEARCH for string criteria (e.g. SUBJECT/FROM/HEADER) may be unreliable on some Tencent Exmail servers; prefer client-side filtering via fetch-emails.sh | rg/grep.

Gmail

• IMAP: imap.gmail.com:993
• SMTP: smtp.gmail.com:587 (STARTTLS)
• Requires "Less secure app access" or App Password
• May need OAuth2 for enhanced security

Outlook/Office 365

• IMAP: outlook.office365.com:993
• SMTP: smtp.office365.com:587
• Requires modern authentication

Technical Details

Why curl instead of rustls?

The rustls TLS library has compatibility issues with some email providers (notably Tencent Enterprise Mail). curl with OpenSSL/LibreSSL provides:

• Better TLS handshake compatibility
• Wider cipher suite support
• Proven reliability with enterprise email systems

IMAP vs POP3

This skill uses IMAP (not POP3) because:

• IMAP supports folder management
• Messages remain on server
• Better for multi-device access
• More flexible search and filtering

Future Enhancements

Potential improvements (not yet implemented):

• Server-side IMAP SEARCH (subject/sender/date; provider-dependent)
• Attachment handling
• HTML email composition
• Email filtering and rules
• OAuth2 authentication support
• Batch operations

References

• RFC 3501 - IMAP4rev1
• RFC 5321 - SMTP
• curl IMAP documentation
• macOS Keychain security command