front-mailparser
v0.6.1-5
Published
Asynchronous and non-blocking parser for mime encoded e-mail messages
Downloads
15
Readme
MailParser
MailParser is an asynchronous and non-blocking parser for node.js to parse mime encoded e-mail messages. Handles even large attachments with ease - attachments can be parsed in chunks and streamed if needed.
MailParser parses raw source of e-mail messages into a structured object.
No need to worry about charsets or decoding quoted-printable or base64 data, MailParser does all of it for you. All the textual output from MailParser (subject line, addressee names, message body) is always UTF-8.
For a 25MB e-mail it takes less than a second to parse if attachments are not streamed but buffered and about 3-4 seconds if they are streamed. Expect high RAM usage though if you do not stream the attachments.
If you want to send e-mail instead of parsing it, check out my other module Nodemailer.
ICONV NOTICE
Since v0.4 node-iconv
is not included by default as a dependency. If you need to support encodings not covered by iconv-lite
you should add iconv
as a dependency to your own project so mailparser
could pick it up.
Support mailparser development
Installation
npm install mailparser
Usage
Require MailParser module
var MailParser = require("mailparser").MailParser;
Create a new MailParser object
var mailparser = new MailParser([options]);
Options parameter is an object with the following properties:
- debug - if set to true print all incoming lines to console
- streamAttachments - if set to true, stream attachments instead of including them
- unescapeSMTP - if set to true replace double dots in the beginning of the file
- defaultCharset - the default charset for text/plain and text/html content, if not set reverts to Latin-1
- showAttachmentLinks - if set to true, show inlined attachment links
<a href="cid:...">filename</a>
MailParser object is a writable Stream - you can pipe directly
files to it or you can send chunks with mailparser.write
When the headers have received, "headers" is emitted. The headers have not been pre-processed (except that mime words have been converted to UTF-8 text).
mailparser.on("headers", function(headers){
console.log(headers.received);
});
When the parsing ends an 'end'
event is emitted which has an
object with parsed e-mail structure as a parameter.
mailparser.on("end", function(mail){
mail; // object structure for parsed e-mail
});
Parsed mail object
- headers - unprocessed headers in the form of -
{key: value}
- if there were multiple fields with the same key then the value is an array - from - an array of parsed
From
addresses -[{address:'[email protected]',name:'Sender Name'}]
(should be only one though) - to - an array of parsed
To
addresses - cc - an array of parsed
Cc
addresses - bcc - an array of parsed 'Bcc' addresses
- subject - the subject line
- references - an array of reference message id values (not set if no reference values present)
- inReplyTo - an array of In-Reply-To message id values (not set if no in-reply-to values present)
- priority - priority of the e-mail, always one of the following: normal (default), high, low
- text - text body
- html - html body
- date - date field as a
Date()
object. If date could not be resolved or is not found this field is not set. Check the original date string fromheaders.date
- attachments - an array of attachments
Decode a simple e-mail
This example decodes an e-mail from a string
var MailParser = require("mailparser").MailParser;
var mailparser = new MailParser();
var email = "From: 'Sender Name' <[email protected]>\r\n"+
"To: 'Receiver Name' <[email protected]>\r\n"+
"Subject: Hello world!\r\n"+
"\r\n"+
"How are you today?";
// setup an event listener when the parsing finishes
mailparser.on("end", function(mail_object){
console.log("From:", mail_object.from); //[{address:'[email protected]',name:'Sender Name'}]
console.log("Subject:", mail_object.subject); // Hello world!
console.log("Text body:", mail_object.text); // How are you today?
});
// send the email source to the parser
mailparser.write(email);
mailparser.end();
Pipe file to MailParser
This example pipes a readableStream
file to MailParser
var MailParser = require("mailparser").MailParser;
var mailparser = new MailParser();
var fs = require("fs");
mailparser.on("end", function(mail_object){
console.log("Subject:", mail_object.subject);
});
fs.createReadStream("email.eml").pipe(mailparser);
Attachments
By default any attachment found from the e-mail will be included fully in the final mail structure object as Buffer objects. With large files this might not be desirable so optionally it is possible to redirect the attachments to a Stream and keep only the metadata about the file in the mail structure.
mailparser.on("end", function(mail_object){
mail_object.attachments.forEach(function(attachment){
console.log(attachment.fileName);
});
});
Default behavior
By default attachments will be included in the attachment objects as Buffers.
attachments = [{
contentType: 'image/png',
fileName: 'image.png',
contentDisposition: 'attachment',
contentId: '5.1321281380971@localhost',
transferEncoding: 'base64',
length: 126,
generatedFileName: 'image.png',
checksum: 'e4cef4c6e26037bcf8166905207ea09b',
content: <Buffer ...>
}];
The property generatedFileName
is usually the same as fileName
but if several
different attachments with the same name exist or there is no fileName
set, an
unique name is generated.
Property content
is always a Buffer object (or SlowBuffer on some occasions)
Attachment streaming
Attachment streaming can be used when providing an optional options parameter
to the MailParser
constructor.
var mp = new MailParser({
streamAttachments: true
}
This way there will be no content
property on final attachment objects
(but the other fields will remain).
To catch the streams you should listen for attachment
events on the MailParser
object. The parameter provided includes file information (contentType
,
fileName
, contentId
) and a readable Stream object stream
.
var mp = new MailParser({
streamAttachments: true
}
mp.on("attachment", function(attachment, mail){
var output = fs.createWriteStream(attachment.generatedFileName);
attachment.stream.pipe(output);
});
generatedFileName
is unique for the parsed mail - if several attachments with
the same name exist, generatedFileName
is updated accordingly. Also there
might not be fileName
parameter at all, so it is better to rely on
generatedFileName
.
Testing attachment integrity
Attachment objects include length
property which is the length of the attachment
in bytes and checksum
property which is a md5
hash of the file.
Running tests
Install MailParser with dev dependencies
npm install --dev mailparser
And then run
npm test mailparser
There aren't many tests yet but basics should be covered.
Issues
S/MIME
Currently it is not possible to verify signed content as the incoming text is split to lines when parsing and line ending characters are not preserved. One can assume it is always \r\n but this might not be always the case.
Seeking
Due to the line based parsing it is also not possible to explicitly state the beginning and ending bytes of the attachments for later source seeking. Node.js doesn't support the concept of seeking very well anyway.
License
MIT