EmailValidator

EmailValidator is a simple node.js helper library to check an email address's validity without sending a single email.

Why?

If you send commercial email you know getting your email delivered is very hard - even if you follow all the rules. A high bounce rate (above 3%) can cause your delivery rates to drop dramatically. By validating email addresses that your team may collect over the phone and hand enter into a CRM you can protect yourself and decrease your bounce rate. Thereby increasing your email marketing effectiveness.

Features

• Very basic email syntax check.
• Check for valid MX records
• If no MX records are found, check for valid A record
• Verify MX/A has a listening email server
• Redis used as a cache to improve speed and avoid bombarding mail servers

Risks

It is possible that if you query a single provider too much that the email provider will block you. We've implemented a Redis cache to mitigate this.

It is possible that you perform a validity check when an ISP's SMTP server is down, inaccurately noting it as offline.

To do: Right now we just query the first MX record instead of all of them. The code should be refactored to loop through each MX record asynchronously. Anyone care to help?

Installation

setup redis

./src/redis-server /usr/redis-2.8.9/redis.conf

We'll just use the default port. If you have something custom, then you'll need to configure the connection.

Next, install the package

npm install emailvalidator

Using as a node module

In the simplest form you can just call:

var options = {
    externalIpAddress: '93.184.216.119', 
    redisPort: 6379, 
    redisHost: '127.0.0.1'
}
require('emailvalidator').checkEmailAddress('[email protected]', options, callback);

The parameters are optional, but should you lave a blank externalIpAddress you may affect the accuracy of the program.

To lookup your external IP address, just call

require('emailvalidator').getExternalIp(callback)

the callback is function(error, response)

the response object is:

{
    "email": "[email protected]",
    "valid": false,
    "reason": "no server to receive mail. cannot connect to mail exchanger"
}

Using as a Microservice

Built into this module is a webserver that responds to GET requests on /:email

To start this webserver automatically, just run npm start

Otherwise, you can run it programatically by calling

var options = {
    // defaults to 3000
    port: integer,
    // if null/empty we will look this up automatically
    externalIpAddress: '',
    // defaults to 127.0.0.1
    redisHost: integer,
    // defaults to 6379
    redisPort: integer
}

require('emailvalidator').startWebServer(options)