JordiPlana

This plugin hooks the normal WordPress workflow in order to determine if the request is processing will cause a 404 HTTP error. In that case it prevents WordPress to do any other processing and sends the user to the page defined in the plugin options.
A working and simple solution.
For more information about this plugin you can check <a href="http://jordiplana.com/404-simple-redirect-plugin-for-wordpress" title="404 Simple Redirect Plugin for WordPress" rel="nofollow ugc">the official page</a>.

404 Simple Redirect

This plugin hooks the normal Wordpress workflow in order to determine if the request is processing will cause a 404 HTTP error.

doublesharp

Use the <code>[remote_content url="http://www.example.com"]</code> shortcode to import remotely hosted content into your posts or page using <code>cURL</code>. Supports HTML <code>GET</code> and <code>POST</code>, <code>BASIC</code> authentication, HTML entity escaping/encoding, CSS selectors and element removal, regular expression replacements, and caching.
This shortcode will let you…
<ul>
<li>Display the contents of a document stored in Subversion or Git repository into a post where it can then be formatted using SyntaxHighlighter.</li>
<li>Quickly integrate content from other CMS systems, for example a company intranet.</li>
<li>Control access to protected data using WordPress’ permissions.</li>
<li>Select and remove DOM elements based on CSS selectors (like jQuery).</li>
<li>Find and replace text based on PHP regular expressions.</li>
<li>HTML encode the remote content.</li>
<li>Strip tags from the remote content.</li>
<li>Cache the remote content.</li>
</ul>
<h4>Usage</h4>
Attributes 
 [remote_content url=”http://www.example.com” method=”GET” timeout=”10″ userpwd=”username:password” htmlentities=”false” strip_tags=”false” decode_atts=”false” selector=”body” remove=”img” find=”~domain.com~” replace=”new-domain.com” cache=”true” cache_ttl=”3600″]
<ul>
<li><code>url</code>
<ul>
<li>The url that you want to request.</li>
</ul>
</li>
<li><code>method=[</code><code>GET</code><code>| POST ]</code>
<ul>
<li>The HTTP request type, defaults to <code>GET</code>.</li>
</ul>
</li>
<li><code>params="key=value, foo, bar"</code>
<ul>
<li>The keys listed here will be parsed from the querystring and appended to the <code>url</code>. Separate keys by with commas. If the value is not found in the querystring the default value can be specified by placing it after an equals sign: <code>parameter=default</code>.</li>
</ul>
</li>
<li><code>timeout=[ 0-9...</code><code>10</code><code>]</code>
<ul>
<li>The request timeout in seconds if it can’t be fetched from the cache, defaults to <code>10</code> seconds.</li>
</ul>
</li>
<li><code>userpwd=[</code>**<code>username:password</code> **<code>| post_meta | site_option | constant ]</code>
<ul>
<li>The username and password to send for <code>BASIC</code> authentication. It is recommended to not set the username and password directly in the tag, as YOUR PASSWORD WILL BE PUBLICLY VISIBLE ON YOUR WEBSITE IF THIS PLUGIN IS DISABLED, and instead use one of the other options. By order of priority, if the value matches a post <code>meta_key</code> the <code>meta_value</code> is used, if it matches a <code>site_option</code> the <code>option_value</code> is used, and if it matches a constant the constant value is used, otherwise the string data is parsed as is. The format is <code>username:password</code>.</li>
</ul>
</li>
<li><code>htmlentities=[</code><code>false</code><code>| true ]</code>
<ul>
<li>If you want to HTML encode the content for display, set to <code>true</code>, defaults to <code>false</code>.</li>
</ul>
</li>
<li><code>strip_tags=[</code><code>false</code><code>| true ]</code>
<ul>
<li>strip all HTML tags from the response, defaults to <code>false</code>.</li>
</ul>
</li>
<li><code>decode_atts=[</code><code>false</code><code>| true ]</code>
<ul>
<li>The SyntaxHighlighter plugin will HTML encode your shortcode attributes, so <code>attr="blah"</code> becomes <code>attr=&quot;blah&quot;</code>. This fixes it to the intended value when set to <code>true</code>, defaults to <code>false</code>.</li>
</ul>
</li>
<li><code>selector=[ CSS Selectors... ]</code>
<ul>
<li>The CSS selector or comma separated list or selectors for the content you would like to display, for example <code>div.main-content</code> or <code>div.this-class #this-id</code>, defaults to the entire document.</li>
</ul>
</li>
<li><code>remove=[ CSS Selectors... ]</code>
<ul>
<li>The CSS selector or comma separated list or selectors for the content that you would like to remove from the content, for example <code>h2.this-class</code> or <code>div#this-id</code>, defaults to no replacement.</li>
</ul>
</li>
<li><code>find=[ regex ]</code>
<ul>
<li>Use a PHP regular expression to find content and replace it based on the <code>replace</code> attribute, for example <code>~http://([^\.]*?)\.example\.com~</code>, defaults to disabled.</li>
</ul>
</li>
<li><code>replace=[ regex ]</code>
<ul>
<li>The replacement text to use with the results of the <code>find</code> regular expression, for example <code>https://\\1.new-domain.com</code>, defaults to empty string replacement.</li>
</ul>
</li>
<li><code>cache=[</code><code>true</code><code>| false ]</code>
<ul>
<li>Set to <code>false</code> to prevent the contents from being cached in the WP-Cache/WordPress transients, defaults to <code>true</code> for performance.</li>
</ul>
</li>
<li><code>cache_ttl=[ 0-9...</code><code>3600</code><code>]</code>
<ul>
<li>Set the number of seconds to cache the results, using 0 for “as long as possible”, defaults to 3600 seconds (one hour).</li>
</ul>
</li>
</ul>
Shortcode Contents + POST 
If there is any content within the shortcode tags, it is sent as part of the request to the remote server.
<pre><code>[remote_content url="http://www.example.com" method="POST"]
{ json: { example: some_data } }
[/remote_content]
</code></pre>

Remote Content Shortcode

Embed remote content into a post or page using a shortcode. Easily select and replace DOM elements.

404 Simple Redirect vs Remote Content Shortcode