Mailchimp has a really simple means of automating the sending of your blog content as a Campaign (email newsletter); RSS-to-Email. Most blogging services such as WordPress, Blogger, Weebly and Wix automatically create a feed in the form of RSS or Atom. The feed contains the content of your blog posts in a way that Mailchimp and others understand and can use the content. Mailchimp is able to extract your posts from the feed and add the post content into a Campaign. This means that the creation and sending of your blog content, in an email campaign, can be fully automated.
Setting up Mailchimp RSS Campaigns
The simplest means of setting up RSS-to-Email is to use one of the RSS templates that Mailchimp provides for no cost. Next simplest is to either use the RSS content blocks in the Mailchimp content editor or, for even more options, use RSS Merge Tags. It’s important to understand that Mailchimp can only send, or use, content that is in the feed as created by your blog. If you’re certain that your Campaign and RSS Merge Tags (or content blocks) are all setup correctly and the content in the send Campaign isn’t what you expect, then check that the content in the feed from your blogging service is what it should be.
— Gary Eckstein (@ecksteing) January 29, 2015
Images are too large for my email Campaign
Quite a common issue, if you choose to show the full content of your blog posts in your Mailchimp Campaign, is that images are quite wide and look a bit strange in the Campaign. This is particularly an issue if you embed large images in your blog Posts. Quite simply, the typical free templates as provided by Mailchimp are 600px wide (so that they look good on almost all email readers). Blog and website widths are usually around 1000px to 1200px wide. If you insert an image on your blog that is full width then it will most probably be wider than the 600px width of a typical Mailchimp template and therefore bits of the template will stretch to accommodate the image width.
The simplest way around this problem is to either change the content of your RSS feed to exclude images (this will be done in the settings of your blog) or, in Mailchimp, use the merge tag
*|RSSITEM:CONTENT|* or similar (i.e. don’t show the full content of each post but rather a summary).