### Install mailsplit

Source: https://github.com/zone-eu/mailsplit/blob/master/README.md

Install the mailsplit module using npm. This command adds mailsplit as a dependency to your project.

```bash
npm install mailsplit --save
```

--------------------------------

### Pipe message stream through Splitter and Joiner

Source: https://github.com/zone-eu/mailsplit/blob/master/README.md

This example demonstrates how to pipe a message stream through the MailSplit Splitter and Joiner to process and output the message to stdout. Ensure you have the 'mailsplit' module installed.

```javascript
let Splitter = require('mailsplit').Splitter;
let Joiner = require('mailsplit').Joiner;
let splitter = new Splitter();
let joiner = new Joiner();
// pipe a message source to splitter, then joiner and finally to stdout
someMessagStream
    .pipe(splitter)
    .pipe(joiner)
    .pipe(process.stdout);
```

--------------------------------

### Handle Parsed Email Data

Source: https://github.com/zone-eu/mailsplit/blob/master/README.md

Process the data emitted by the Splitter stream. This example demonstrates how to handle 'node', 'data', and 'body' types to extract headers, multipart structures, and leaf element bodies.

```javascript
let Splitter = require('mailsplit').Splitter;
let splitter = new Splitter();
// handle parsed data
splitter.on('data', data => {
    switch (data.type) {
        case 'node':
            // node header block
            process.stdout.write(data.getHeaders());
            break;
        case 'data':
            // multipart message structure
            // this is not related to any specific 'node' block as it includes
            // everything between the end of some node body and between the next header
            process.stdout.write(data.value);
            break;
        case 'body':
            // Leaf element body. Includes the body for the last 'node' block. You might
            // have several 'body' calls for a single 'node' block
            process.stdout.write(data.value);
            break;
    }
});
// send data to the parser
someMessagStream.pipe(splitter);
```

--------------------------------

### Initialize Splitter Stream

Source: https://github.com/zone-eu/mailsplit/blob/master/README.md

Initialize a new Splitter stream instance. Options can be provided to configure parsing behavior, such as ignoring embedded messages or limiting header size.

```javascript
let Splitter = require('mailsplit').Splitter;
let splitter = new Splitter(options);
```

--------------------------------

### Stream Specific JPEG Nodes from Emails

Source: https://github.com/zone-eu/mailsplit/blob/master/README.md

Utilize Streamer to extract nodes matching a filter function. Pipe a Splitter stream into Streamer and its output to a Joiner. The Streamer emits a 'node' event for matching nodes, providing a decoder for content and a done callback. Ensure data.done() is called after processing.

```javascript
let Splitter = require('mailsplit').Splitter;
let Joiner = require('mailsplit').Joiner;
let Streamer = require('mailsplit').Streamer;
let fs = require('fs');
let splitter = new Splitter();
let joiner = new Joiner();
let streamer = new Streamer(node => node.contentType === 'image/jpeg');
streamer.on('node', data => {
    // write to file
    data.decoder.pipe(fs.createWriteStream(data.node.filename || 'image.jpg'));
    data.done();
});
// pipe a message source to splitter, then streamer, then joiner and finally to stdout
someMessagStream
    .pipe(splitter)
    .pipe(streamer)
    .pipe(joiner)
    .pipe(process.stdout);
```

--------------------------------

### Rewrite Specific HTML Nodes in Emails

Source: https://github.com/zone-eu/mailsplit/blob/master/README.md

Use Rewriter to modify nodes matching a filter function. Pipe a Splitter stream into Rewriter and its output to a Joiner. The Rewriter emits a 'node' event for matching nodes, providing access to the node, a decoder for its content, and an encoder to write modified content.

```javascript
let Splitter = require('mailsplit').Splitter;
let Joiner = require('mailsplit').Joiner;
let Rewriter = require('mailsplit').Rewriter;
let splitter = new Splitter();
let joiner = new Joiner();
let rewriter = new Rewriter(node => node.contentType === 'text/html');
rewriter.on('node', data => {
    // manage headers with node.headers
    node.headers.add('X-Processed-Time', new Date.toISOString());
    // do nothing, just reencode existing data
    data.decoder.pipe(data.encoder);
});
// pipe a message source to splitter, then rewriter, then joiner and finally to stdout
someMessagStream
    .pipe(splitter)
    .pipe(rewriter)
    .pipe(joiner)
    .pipe(process.stdout);
```

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