Summary:

When creating a new Mailchimp campaign the following error message is displayed:

 
  
Symptoms:

The Mailchimp campaign was created with the following details:

  


Cause:

The cause of this issue was that the "Let users pick plain-text or HTML emails" checkbox in the list settings on the MailChimp website was checked.

This can be seen in the mailchimp.log file:

ERROR [http-apr-9009-exec-2]: 30-Jan-2015 12:19:52.590 Campaign_InvalidContent!

Status:

With reference to following Mailchimp KB I followed the steps and this issue is resolved

http://kb.mailchimp.com/lists/growth/how-to-change-list-name-and-defaults

You need to open Mailchimp website and open the List which is used in CRM, go to List settings and click on “List name & defaults” and uncheck “Let users pick plain-text or HTML emails” Save it and try now.

More Info:

As per the first part of the error message the Email address should be valid and there should be no Email address in Sender’s name.