npm package: @regru/mailcheck
Description: A jQuery plugin that suggests a right domain when your users misspell it in an email address.
Author: Derrick Ko
Latest version: 1.0.4-regru

mailcheck.js
=========

[![TravisCI Build Status](https://secure.travis-ci.org/Kicksend/mailcheck.png?branch=master)](https://travis-ci.org/Kicksend/mailcheck)

The Javascript library and jQuery plugin that suggests a right domain when your users misspell it in an email address.

What does it do?
----------------

When your user types in "user@hotnail.con", Mailcheck will suggest "user@hotmail.com".

Mailcheck will offer up suggestions for top level domains too, and suggest ".com" when a user types in "user@hotmail.cmo".

At [Kicksend](http://kicksend.com), we use Mailcheck to help reduce typos in email addresses during sign ups. It has [reduced our sign up confirmation email bounces by 50%](http://blog.kicksend.com/how-we-decreased-sign-up-confirmation-email-b).

![diagram](http://github.com/Kicksend/mailcheck/raw/master/doc/example.png?raw=true)

See it live in action [here](http://kicksend.com/join).

Installation
------------

For instant use, download `src/mailcheck.min.js` into javascripts directory. Use `src/mailcheck.js` if you want to hack on it, or have your own minimizer.

Usage with jQuery
-----
First, include jQuery and Mailcheck into the page.

```html
<script src="jquery.min.js"></script>
<script src="mailcheck.min.js"></script>
```

Have a text field.

```html
<input id="email" name="email" type="email" />
```

Now, attach Mailcheck to the text field. You can declare an array of domains and top level domains you want to check against.

```html
<script>
var domains = ['hotmail.com', 'gmail.com', 'aol.com'];
var topLevelDomains = ["com", "net", "org"];

var superStringDistance = function(string1, string2) {
  // a string distance algorithm of your choosing
}

$('#email').on('blur', function() {
  $(this).mailcheck({
    domains: domains,                       // optional
    topLevelDomains: topLevelDomains,       // optional
    distanceFunction: superStringDistance,  // optional
    suggested: function(element, suggestion) {
      // callback code
    },
    empty: function(element) {
      // callback code
    }
  });
});
</script>
```

Mailcheck takes in two callbacks, `suggested` and `empty`. We recommend you supply both.

`suggested` is called when there's a suggestion. Mailcheck passes in the target element and the suggestion. The suggestion is an object with the following members:

```js
{
  address: 'test',          // the address; part before the @ sign
  domain: 'hotmail.com',    // the suggested domain
  topLevelDomain: 'com',    // the suggested top level domain
  full: 'test@hotmail.com'  // the full suggested email
}
```
Mailcheck does not want to get in the way of how you can show suggestions. Use the suggestion object to display suggestions in your preferred manner.

`empty` is called when there's no suggestion. Mailcheck just passes in the target element. It is a good idea to use this callback to clear an existing suggestion.

Usage without jQuery
--------------------
Mailcheck is decoupled from jQuery, so its usage without jQuery is almost identical.

Using the example from above, you would call `Kicksend.mailcheck.run` instead.

```html
<script>
Kicksend.mailcheck.run({
  email: yourTextInput.value,
  domains: domains,                       // optional
  topLevelDomains: topLevelDomains,       // optional
  distanceFunction: superStringDistance,  // optional
  suggested: function(suggestion) {
    // callback code
  },
  empty: function() {
    // callback code
  }
});
</script>
```

The rest works similarly. In fact, the Mailcheck jQuery plugin just wraps `Kicksend.mailcheck.run`.

Domains
-------
Mailcheck has inbuilt defaults if the `domains` or `topLevelDomains` options aren't provided. We still recommend supplying your own domains based on the distribution of your users.

The included default domains are yahoo.com, google.com, hotmail.com, gmail.com, me.com, aol.com, mac.com, live.com, comcast.net, googlemail.com, msn.com, hotmail.co.uk, yahoo.co.uk, facebook.com, verizon.net, sbcglobal.net, att.net, gmx.com, and mail.com.

The included default top level domains are com, net, org, info, edu, gov, co.uk, and mil.

Customization
-------------
The Mailcheck jQuery plugin wraps Kicksend.mailcheck. The prime candidates for customization are the methods
`Kicksend.mailcheck.findClosestDomain` and `Kicksend.mailcheck.stringDistance`.

Mailcheck currently uses the [sift3](http://siderite.blogspot.com/2007/04/super-fast-and-accurate-string-distance.html) string similarity algorithm by [Siderite](http://siderite.blogspot.com/). You can modify the inbuilt string distance function, or pass in your own when calling Mailcheck.

Since Mailcheck runs client side, keep in mind file size, memory usage, and performance.

Tests
-----

Mailcheck is tested with [Jasmine](http://pivotal.github.com/jasmine/). Load `spec/spec_runner.html` in your browser to run the tests.

Contributing
------------

Let's make Mailcheck awesome. We're on the lookout for maintainers and [contributors](https://github.com/Kicksend/mailcheck/contributors).

And do send in those pull requests! To get them accepted, please:

- Test your code. Add test cases to `spec/mailcheckSpec.js`, and run it across browsers (yes, including IE).

- Minify the plugin. [Google's Closure Compiler](http://closure-compiler.appspot.com/home) is a good one.

Upcoming features, bugs and feature requests are managed in Issues.

Who's using Mailcheck?
-----------------------

- [Kicksend](http://kicksend.com/)
- [Dropbox](http://dropbox.com/)
- [Flotype](http://flotype.com/)
- [Kickstarter](http://kickstarter.com/)
- [Kippt](http://kippt.com/)
- [Minecraft](http://minecraft.net/)
- [Prispy](http://prispy.com/)
- [SB Nation](http://sbnation.com/)
- [Show Space](http://show-space.com/)
- [The Verge](http://theverge.com/)
- [Uber](http://uber.com/)
- [Khan Academy](http://khanacademy.org/)

Do you use Mailcheck? [Tweet me](http://twitter.com/derrickko) your link.

Related links
-------------

- [Two ways to reduce bounced welcome emails](http://blog.postmarkapp.com/post/19685472721/two-ways-to-reduce-bounced-welcome-emails) by [Postmark](http://postmark.com)

- [MooTools port](https://github.com/DimitarChristoff/mailcheck) by [Dimitar Christoff](https://github.com/DimitarChristoff)

- [WordPress Plugin](https://github.com/bmoredrew/mailcheck-wordpress-plugin/) by [Drew Poland](https://github.com/bmoredrew)

- [WordPress e-Commerce Plugin](http://wordpress.org/extend/plugins/e-commerce-mailcheck/)

- [Mailcheck for Drupal](http://drupal.org/project/Mailcheck) by [Martin Elvar](https://twitter.com/MartinElvar)

Core Team
-------

- Derrick Ko, [Kicksend](http://kicksend.com), [@derrickko](http://twitter.com/derrickko). Created Mailcheck.
- Wei Lu, [neo](http://neo.com), [@luweidewei](http://twitter.com/luweidewei).

License
-------

Copyright (c) 2012 [Receivd, Inc.](http://kicksend.com)

Licensed under the MIT License.