pixl-mail

Table of Contents

• Overview
• Usage
  • Placeholder Substitution
  • Loading From Files
  • Attachments
  • HTML Emails
  • Options
  • Logging
  • Debugging
• License

Overview

This module provides a very simple e-mail sender, which leans heavily on the awesome nodemailer package. It layers on the ability to pass in a complete e-mail message with headers and body in one string (or file), and optionally perform placeholder substitution using sub() from the pixl-tools package. Auto-detects HTML or plain text e-mail body, and supports custom headers and attachments as well.

Usage

Use npm to install the module:

npm install pixl-mail

Then use require() to load it in your code:

const PixlMail = require('pixl-mail');

Instantiate a mailer object and pass in the SMTP hostname (defaults to 127.0.0.1) and the port number (defaults to 25):

let mail = new PixlMail( 'smtp.myserver.com', 25 );
let mail = new PixlMail( '127.0.0.1' );
let mail = new PixlMail();

Send mail using the send() method. Pass in the complete e-mail message as a multi-line string including To, From and Subject headers, and a callback:

let message = 
	"To: [e-mail]\n" + 
	"From: [e-mail]\n" + 
	"Subject: State Budget\n" +
	"\n" +  
	"Dear Mr. President,\nOur state needs more money.\n";

mail.send( message, function(err) {
	if (err) console.error( "Mail Error: " + err );
} );

For multiple recipients, simply separate them by commas on the To line. You can also specify Cc and/or Bcc headers, as well as any custom MIME headers.

Placeholder Substitution

The library supports a simple e-mail templating system, where you can insert [bracket_placeholders] in your e-mail message, and have the library fill them with appropriate content from a separate object. This feature uses the sub() function from the pixl-tools package.

As an example, imagine a welcome e-mail for a new user who has signed up for your app. You have the welcome e-mail "template" stored separately, and want to fill in the user's e-mail address, full name and username at sending time. Here is how to do this:

// email template
let message = 
	"To: [email]\n" + 
	"From: [e-mail]\n" + 
	"Subject: Welcome to My App, [full_name]!\n" +
	"\n" +  
	"Dear [full_name],\nWelcome to My App!  Your username is '[username]'.\n";

// placeholder args
let user = {
	username: "jhuckaby",
	full_name: "Joseph Huckaby",
	email: "[e-mail]"
};

mail.send( message, user, function(err) {
	if (err) console.log(err);
} );

So in this case our e-mail template has several placeholders, including [email], [full_name] and [username]. These are pulled from the user object which is passed to send() as the 2nd argument. So the final e-mail that would be sent is:

To: [e-mail]
From: [e-mail]
Subject: Welcome to My App, Joseph Huckaby!

Dear Joseph Huckaby,
Welcome to My App!  Your username is 'jhuckaby'.

You can actually use a complex hash / array tree of arguments, and then specify [filesystem/style/paths] or [dot.style.paths] in your placeholders. See the sub() docs for details.

Loading From Files

You can specify a file path instead of the raw message, like this:

let user = {
	username: "jhuckaby",
	full_name: "Joseph Huckaby",
	email: "[e-mail]"
};

mail.send( "conf/emails/new_user_welcome.txt", user, function(err) {
	if (err) console.log(err);
} );

Attachments

To attach files, include an attachments array in your args object, and specify a filename and path for each one. This is passed directly to nodemailer, so you can use all of their attachment features. Example:

let args = {
	attachments: [
		{ filename: "contract.pdf", path: "files/contracts/4573D.PDF" },
		{ filename: "policy.pdf", path: "files/misc/POLICY-2015.PDF" }
	]
};

mail.send( message, args, function(err) {
	if (err) console.error( "Mail Error: " + err );
} );

For details, see the Attachments section in the nodemailer docs.

HTML Emails

If you want to send HTML formatted e-mails, the library will automatically detect this. Just provide the headers in plain text, two end-of-lines, then start your HTML markup. Example:

let message = 
	"To: [e-mail]\n" + 
	"From: [e-mail]\n" + 
	"Subject: State Budget\n" + 
	"\n" + 
	"<h1>Dear Mr. President,</h1>\n<p><b>Please</b> give our state more <i>money</i>.</p>\n";

mail.send( message, function(err) {
	if (err) console.error( "Mail Error: " + err );
} );

Note: Your e-mail body must begin with an HTML tag for it to be recognized.

Options

You can set a number of options using the setOption() or setOptions() methods. These are passed directly to the underlying nodemailer module, so please check out their documentation for details. Examples include setting timeouts, SSL, and authentication.

The setOption() method takes one single key/value to set or replace, while setOptions() accepts an object containing multiple keys/values.

mail.setOption( 'secure', true ); // use ssl
mail.setOption( 'auth', { user: 'fsmith', pass: '12345' } );

mail.setOptions({
	connectionTimeout: 10000, // milliseconds
	greetingTimeout: 10000, // milliseconds
	socketTimeout: 10000 // milliseconds
});

You can also use local sendmail, if you have that configured on your server. To do this, set the following options, and tune as needed:

mail.setOptions({
	"sendmail": true,
	"newline": "unix",
	"path": "/usr/sbin/sendmail"
});

Logging

You can optionally attach a pixl-logger compatible log agent, which will log all the nodemailer debug messages at level 9, with the component column set to Mailer. To use this feature, call the attachLogAgent() method on your class instance, and pass in your pixl-logger instance:

mail.attachLogAgent( logger );

Debugging

The send() method actually returns three arguments: the error (if any), the final composed mail body with headers (after all macro expansion), and a full debug log capture from nodemailer. Here is how to use them:

mail.send( message, function(err, message, log) {
	if (err) console.error( "Mail Error: " + err );
	
	console.log( "Full composed message: " + message );
	
	log.forEach( function(row) {
		console.log( ...row );
	} );
} );

Each log row will contain two elements: the log message itself, and an object containing additional metadata. These come directly from nodemailer. Here is an example excerpt:

Creating transport: nodemailer (6.4.11; +https://nodemailer.com/; SMTP/6.4.11[client:6.4.11])
{"component":"mail","tnx":"create"}

Sending mail using SMTP/6.4.11[client:6.4.11]
{"component":"mail","tnx":"transport","name":"SMTP","version":"6.4.11[client:6.4.11]","action":"send"}

Resolved localhost as ::1 [cache miss]
{"component":"smtp-connection","sid":"N5uAYhHPKsY","tnx":"dns","source":"localhost","resolved":"::1","cached":false}

Connection established to ::1:25
{"component":"smtp-connection","sid":"N5uAYhHPKsY","tnx":"network","localAddress":"::1","localPort":53068,"remoteAddress":"::1","remotePort":25}

220 joemax.local ESMTP Postfix
{"component":"smtp-connection","sid":"N5uAYhHPKsY","tnx":"server"}

EHLO joemax.local
{"component":"smtp-connection","sid":"N5uAYhHPKsY","tnx":"client"}

License

The MIT License (MIT)

Copyright (c) 2015 - 2024 Joseph Huckaby.

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.