MB MB

This plugin makes it easy to display the featured images of your posts in mailchimp RSS newsletters.
Once activated this plugin will add the following to your sites default rss feed:
To the rss name space declarations:
<pre><code> xmlns:media="http://search.yahoo.com/mrss/"
</code></pre>
To each individual item (if it has a featured image):
<pre><code><media:content url="[url]" type="[mimetype]" medium="image" width="100%" height="auto">
 <media:description type="plain"><![CDATA[title]]></media:description>
</media:content>
</code></pre>
The featured images are not inserted directly into the content of your posts, so you have full control over where and how to present them. 
If you send out newsletters using a Mailchimp RSS based Campaign, simply place the *|RSSITEM:IMAGE|* merge-tag in your mail template where you want the featured image inserted.
This plugin contains
<ul>
<li>100% clean lightweight code.</li>
<li>0% JS</li>
<li>0% CSS</li>
<li>0% options</li>
</ul>
The plugin uses the hooks ‘rss2_ns’ and ‘rss2_item’, part of the WordPress core API. 
Tested with WP 3.7.1 and MailChimp Dec 2013
Contribute via <a href="https://github.com/mikkelbreum/MB-ImageChimp-RSS-Feed-Enhancer/" title="MB-ImageChimp-RSS-Feed-Enhancer" rel="nofollow ugc">github</a>

MB ImageChimp RSS Feed Enhancer

Adds featured images to the default RSS feed for use with MailChimps image merge-tag

5 Star Plugins

Get images in your RSS feed instantly for free. Output blog featured images to Mailchimp RSS email campaigns, ActiveCampaign, Infusionsoft, Hubspot, Zoho, Feedburner, Bloglovin’, Feedly, and other services that use RSS feed data. Also works with WooCommerce product images for product-based RSS campaigns! A trusted plugin, developed in California with over 30,000 active installs and 75+ five star reviews. We actively answer every support forum thread.
Featured Images In RSS was built for content marketers. Easy set-up with minimal configuration to get up and running in minutes.
This plugin is forever free. Upgrade to Premium to unlock powerful features for content marketing. Developed and supported in the United States by 5 Star Plugins.
Free Features:
<ul>
<li>Can be used in any marketing automation service.</li>
<li>Select Featured Image Size: thumbnail, medium, large, any theme-specific sizes, or full size</li>
<li>Select Image Position: left above text, left text wrap, right text wrap, or centered above text</li>
<li>Padding: Instantly set the spacing between the image and the body text.</li>
<li>Feedly: Supports webfeedsFeaturedVisual class name on image HTML.</li>
<li>WooCommerce: Instantly add product photos to the product RSS feeds, and create product-based RSS campaigns.</li>
<li>Free support through the WordPress Support Forum.</li>
<li>Plugin updates with free version new features, fixes and security patches.</li>
</ul>
<blockquote>
Premium Upgrade Features
Enjoy a 14-day free trial no credit card required. Check out this full suite of image customization features for professional marketing.
<ul>
<li>Tech Support: Expert support in the U.S. to help get everything working and looking great.</li>
<li>Media and Enclosure Tags: Some services require it and it allows you to custom design email templates.</li>
<li>Use Media tag images only: Fix duplicate images issues when using image tags for advanced template designs.</li>
<li>Custom Image Sizes: Completely customize the size of image display for RSS feeds.</li>
<li>Feature Body Image: No featured photos set? No problem. Use the first photo from the body of posts.</li>
<li>Disable Responsive Images: Helps fix services that have issues with the responsive image code, like Mailchimp’s Preview.</li>
<li>Exclude Categories: Exclude unwanted categories not meant to be included in the RSS feed, like Homepage or Featured categories.</li>
<li>Custom Content in Feeds: Add custom content (text or HTML) before or after the post such as backlinks or ads.</li>
<li>Publish Delay: Add a time buffer to new posts from instantly hitting the RSS feed to safeguard from typos or accidents.</li>
<li>Premium plugin updates with new features, fixes and security patches.</li>
</ul>
</blockquote>
Real Testimonials
<blockquote>
“Must-have for content marketing. This is a super easy way to customize the featured images that appear in the RSS feed – no more ugly pre-populated visuals. I especially love the Mailchimp integration. It’s great to have this much control over our content. Image is everything!” – @morganmariequinn <a href="https://wordpress.org/support/topic/must-have-for-content-marketing/" rel="ugc">Read the review</a>
“Must Have for Featured Image Based Themes & MailChimp Users. For several years my WordPress theme has used featured images at the head of all my posts. The problem is, then, when feeding my RSS feed to MailChimp, that featured image at the head of the post is lost. Sometimes the image is highly crucial to the post (not to mention more enjoyable), so this plugin is a life saver. A must have!” – @ericdye <a href="https://wordpress.org/support/topic/must-have-for-featured-image-based-themes-mailchimp-users/" rel="ugc">Read the review</a>
“It just works – lovely! Great with MailChimp. I installed this plugin, changed the (very simple) settings and the featured images started appearing in my MailChimp campaigns straight away – perfect!” – @barn2media <a href="https://wordpress.org/support/topic/it-just-works-lovely-great-with-mailchimp/" rel="ugc">Read the review</a>
</blockquote>
We promise you’ll love the features this plugin provides for your content marketing automation!
Need help or wish it did something else as well? Use the <a href="https://wordpress.org/support/plugin/featured-images-for-rss-feeds" rel="ugc">Support</a> tab to submit your thoughts.
Love this plugin? Please submit a <a href="https://wordpress.org/support/plugin/featured-images-for-rss-feeds/reviews/?filter=5#new-post" rel="ugc">rating and review</a>, I’d appreciate your praise. (Have an issue? Post to the support forums before leaving a bad review.)

Featured Images in RSS for Mailchimp & More

There's a setting screen with just a few options, but a few is all you need, to select which size image to include in the feed, image alignment, how much padding, and whether the image is a link to the post.

Does what it says it will do, little fuss

I installed a plugin to block the ads from this plugin! It works but these messages are too boring.

too much ads

Send images to RSS instantly for free. Output blog or WooCommerce photos to Mailchimp RSS email campaigns, ActiveCampaign, Hubspot, Feedly and more.

MB ImageChimp RSS Feed Enhancer vs Featured Images in RSS for Mailchimp & More