MailOxide

A blazing fast, parallel EML to MBOX converter written in Rust.

  ______   __  __   _          _______    ____      __  __   ____     ____   __   __
 |  ____| |  \/  | | |        |__   __|  / __ \    |  \/  | |  _ \   / __ \  \ \ / /
 | |__    | \  / | | |           | |    | |  | |   | \  / | | |_) | | |  | |  \ V / 
 |  __|   | |\/| | | |           | |    | |  | |   | |\/| | |  _ <  | |  | |   > <  
 | |____  | |  | | | |____       | |    | |__| |   | |  | | | |_) | | |__| |  / . \ 
 |______| |_|  |_| |______|      |_|     \____/    |_|  |_| |____/   \____/  /_/ \_\

Features

• Convert single EML file or directory of EML files to MBOX format
• Parallel processing for high performance on large directories
• Memory-efficient processing with chunked approach
• Progress reporting for large conversions
• Standards-compliant MBOX format
• Simple command-line interface

Installation

Using Cargo

cargo install mailoxide

From Source

git clone https://github.com/solastrius/mailoxide.git
cd mailoxide
cargo build --release

The compiled binary will be available at target/release/mailoxide.

Usage

mailoxide [INPUT] [OUTPUT]

Where:

• INPUT is a path to an EML file or a directory containing EML files (default: "input")
• OUTPUT is the destination directory for the MBOX file (default: "input")

Examples

1. Convert a single EML file to MBOX:

mailoxide /path/to/email.eml /path/to/output

2. Convert all EML files in a directory:

mailoxide /path/to/email/directory /path/to/output

3. Use default paths:

mailoxide

This will look for an "input" directory in the current path, find all EML files there, and save the output to the same "input" directory as "output.mbox".

Performance

MailOxide is designed to be extremely fast, even with large email collections. It achieves this through:

• Parallel processing with Rayon
• Memory-efficient chunked processing
• Buffered file I/O
• Progress reporting for large conversions

In real-world testing, it successfully processed over 30,000 emails (3.6GB) in minutes.

License

MIT

Credits

This is a Rust rewrite and optimization of the original Python eml2mbox tool by nick88msn.