Features

• Lightning Fast: Single-transaction writes with optimized SQLite settings (WAL mode, memory mapping, large cache)
• Smart Filtering: Automatically excludes Spam and Trash by default (configurable)
• Auto-Incrementing Filenames: Creates dated databases (e.g., 2025-11-03-emails.db) that auto-increment to avoid overwriting
• Robust Date Parsing: Handles 20+ malformed date formats commonly found in email archives
• Progress Indicator: Modern spinner shows real-time progress and skipped email counts
• Full-Text Search Ready: Creates indexes on common fields for instant queries

Building from Source

# Build release binary
cargo build --release

# Binary will be at ./target/release/mbox2db

Examples

Basic Conversion (Default Behavior)

# Filters out Spam/Trash, creates dated output file
mbox2db all-mail.mbox
# Output: 2025-11-04-emails.db

# Running again on the same day creates incremented file
mbox2db all-mail.mbox
# Output: 2025-11-04-emails-0001.db

Include Spam/Trash

# Include spam emails only
mbox2db all-mail.mbox --include-spam

# Include trash emails only
mbox2db all-mail.mbox --include-trash

# Include both spam and trash
mbox2db all-mail.mbox --include-spam-and-trash

Custom Output Path

# Specify custom output location
mbox2db all-mail.mbox -o ~/Documents/my-emails.db

# Overwrite existing file (destructive mode)
mbox2db all-mail.mbox -d -o emails.db

Database Schema

CREATE TABLE emails (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    from_addr TEXT,
    to_addr TEXT,
    cc TEXT,
    bcc TEXT,
    subject TEXT,
    date TEXT,              -- Original email date header
    date_parsed TEXT,       -- Parsed datetime in SQLite format (YYYY-MM-DD HH:MM:SS)
    message_id TEXT,
    in_reply_to TEXT,
    refs TEXT,              -- "references" header
    content_type TEXT,
    body_plain TEXT,
    body_html TEXT
);

-- Indexes for fast queries
CREATE INDEX idx_from ON emails(from_addr);
CREATE INDEX idx_date ON emails(date);
CREATE INDEX idx_date_parsed ON emails(date_parsed);
CREATE INDEX idx_subject ON emails(subject);

More SQL Query Examples

Search by Date

-- Get emails from 2025
SELECT * FROM emails 
WHERE date_parsed LIKE '2025%'
ORDER BY date_parsed DESC;

-- Get emails from date range
SELECT subject, date_parsed, from_addr 
FROM emails 
WHERE date_parsed BETWEEN '2020-01-01' AND '2020-12-31'
ORDER BY date_parsed DESC;

-- Count emails from specific sender
SELECT COUNT(*) FROM emails WHERE from_addr LIKE '%user@example.com%';

Full-Text Search

-- Search email body
SELECT subject, from_addr, date_parsed 
FROM emails 
WHERE body_plain LIKE '%search term%' 
   OR body_html LIKE '%search term%'
ORDER BY date_parsed DESC;

Email Threads

-- Find email threads by message_id/in_reply_to
SELECT * FROM emails 
WHERE in_reply_to = '<some-message-id>'
ORDER BY date_parsed;

Performance Notes

• Optimized SQLite Settings:

  • WAL (Write-Ahead Logging) mode for better concurrency
  • NORMAL synchronous mode for fast writes
  • 64MB cache size
  • 30GB memory mapping
  • Single transaction for all inserts (~10-100x faster)

• Handles Large Files: Tested with multi-GB mbox files containing 80,000+ emails

• Date Parsing: Handles malformed dates including:

  • Double-dash timezones (--0400)
  • Single-digit time components (9:47:11)
  • Two-digit years (Jun 09)
  • Named timezones (Eastern Daylight Time, GMT-0700)
  • Various date formats (7/19/2005 8:11:52 AM)