IMAP Email Migration Tool

A robust and feature-rich tool for migrating email accounts between IMAP servers, preserving all folders, messages, and their status.

✨ Key Features

• Parallel Processing: Migrate up to 5 accounts simultaneously
• Connection Pre-Check: Tests all connections before starting migration
• Automatic Reconnection: Handles connection drops gracefully
• Duplicate Detection: Skip already migrated messages (by Message-ID)
• Advanced Filtering: Filter by date, size, folders
• Dry-Run Mode: Test migration without copying anything
• Detailed Reports: Comprehensive audit reports for each account
• Gmail Support: Full support for Gmail IMAP
• Retry Logic: Configurable automatic retry for failed messages
• Folder Mapping: Rename folders during migration
• Quota Handling: Graceful handling of quota exceeded errors

🚀 Quick Start

1. Extract the Package

unzip imap-migrator-v11-final.zip
cd imap-migrator-v11

2. Create Accounts File

cp accounts.csv.exemplo accounts.csv
nano accounts.csv

Format:

source_email,source_user,source_pass,source_host,dest_email,dest_user,dest_pass,dest_host
user@source.com,user,pass123,imap.source.com,user@dest.com,user,pass456,imap.dest.com

3. Build the Program

Option A: Using the build script (Recommended)

chmod +x build.sh
./build.sh

The script will:

• Check if Go is installed (install if needed)
• Download all dependencies
• Compile the program
• Create imap-migrator executable

Option B: Manual build

go build -o imap-migrator *.go

4. Configure Options (Optional)

Edit config.json to set filters and options.

5. Run

./imap-migrator

Or without building:

go run *.go

📋 Configuration Options

All options are configured in config.json:

• accounts_file: CSV file with accounts (default: "accounts.csv")
• skip_duplicates: Skip already migrated messages
• dry_run: Simulate migration without copying
• max_retries: Number of retry attempts for failed messages
• max_message_size_mb: Skip messages larger than X MB
• flatten_folders: Convert folder hierarchy to flat names
• exclude_folders: Blacklist of folders to skip
• include_folders: Whitelist of folders to migrate (if set, only these are migrated)
• date_from: Migrate only messages >= this date (YYYY-MM-DD)
• date_to: Migrate only messages <= this date (YYYY-MM-DD)
• folder_mapping: Rename folders during migration
• system_folders: Alternative names for system folders
• fetch_batch_size: Number of messages to fetch per request. Lower values (e.g. 500 or 1000) help prevent connection timeouts on very large folders.

📚 Documentation

• QUICKSTART.md - Quick start guide
• FEATURES.md - Complete features documentation
• GMAIL.md - Gmail-specific guide
• CHANGELOG.md - Version history
• REPORT_EXAMPLE.txt - Sample migration report

Portuguese versions available with -ptbr suffix.

🔧 Requirements

• Go 1.19 or higher
• Internet connection
• IMAP access to source and destination servers

📊 Reports

After migration, detailed reports are generated in the reports/ directory with:

• Migration summary (duration, totals)
• Per-folder statistics
• List of errors (if any)
• Skipped messages with reasons

⚠️ Important Notes

• Always test with dry_run: true first
• The tool does NOT delete anything from the source
• For Gmail, use App Passwords (see GMAIL.md)
• All filters are additive (AND logic)

🆘 Support

For issues, questions, or feature requests, send email to:

cabreu@vialink.com.br

📄 License

This tool is provided as-is for email migration purposes.

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Version 1.0 - Full-featured IMAP migration tool with advanced filtering and reporting.