Outlook Email Message (.msg) parser

A parser for Microsoft Outlook .msg files (OLE Compound Document format). Extracts message metadata, body content, recipients, attachments, and transport headers as specified in [MS-OXMSG] and [MS-OXPROPS].

Usage

Add this to your Cargo.toml:

[dependencies]
msg_parser = "0.3"

Quick Start

use msg_parser::Outlook;

fn main() {
    let outlook = Outlook::from_path("email.msg").unwrap();

    println!("From: {} <{}>", outlook.sender.name, outlook.sender.email);
    println!("Subject: {}", outlook.subject);

    for person in &outlook.to {
        println!("To: {} <{}>", person.name, person.email);
    }
    for person in &outlook.cc {
        println!("CC: {} <{}>", person.name, person.email);
    }
}

Parsing from different sources

use msg_parser::Outlook;

// From a file path
let outlook = Outlook::from_path("email.msg").unwrap();

// From a byte slice
let bytes = std::fs::read("email.msg").unwrap();
let outlook = Outlook::from_slice(&bytes).unwrap();

// From any std::io::Read source (file, stdin, network, etc.)
let file = std::fs::File::open("email.msg").unwrap();
let outlook = Outlook::from_reader(file).unwrap();

Saving attachments

let outlook = Outlook::from_path("email.msg").unwrap();

for attach in &outlook.attachments {
    let name = if attach.long_file_name.is_empty() {
        &attach.file_name      // 8.3 short name fallback
    } else {
        &attach.long_file_name // full original filename
    };
    std::fs::write(name, &attach.payload_bytes).unwrap();
}

Detecting embedded messages

Attachments with attach_method == 5 are nested .msg files (embedded messages). You can identify them and handle them separately:

for attach in &outlook.attachments {
    match attach.attach_method {
        1 => println!("{}: regular file", attach.long_file_name),
        5 => println!("{}: embedded .msg", attach.display_name),
        6 => println!("{}: OLE object", attach.display_name),
        _ => println!("{}: other ({})", attach.display_name, attach.attach_method),
    }
}

Message metadata

let outlook = Outlook::from_path("email.msg").unwrap();

// Timestamps (ISO 8601 UTC, empty string if unavailable)
println!("Delivered: {}", outlook.message_delivery_time);
println!("Submitted: {}", outlook.client_submit_time);
println!("Created:   {}", outlook.creation_time);
println!("Modified:  {}", outlook.last_modification_time);

// Classification
println!("Class:       {}", outlook.message_class);  // e.g. "IPM.Note"
println!("Importance:  {}", outlook.importance);      // 0=Low, 1=Normal, 2=High
println!("Sensitivity: {}", outlook.sensitivity);     // 0=Normal, 1=Personal, 2=Private, 3=Confidential

JSON output

let outlook = Outlook::from_path("email.msg").unwrap();
let json = outlook.to_json().unwrap();
println!("{}", json);

Available fields

Requirements

• Rust edition 2024 (rustc 1.85+)

Running the example

cargo run --example parse-email
# or with a specific file:
cargo run --example parse-email -- path/to/email.msg

Running tests

cargo test

Contributions

Feel free to open pull requests to contribute, enhance, or fix bugs.

License: MIT