In September 2014 I wrote a very detailed article on my personal marketing blog that covered the topic of using UTM codes to track traffic sources in detail. Here is the link:
>>What are UTM Codes and how to use them with Google Analytics
Interspire Email Marketer uses UTM codes within the technology to help track web traffic that comes from your email campaigns. When you are sending a campaign and check the box to track the campaign with Google Analytics what you are essentially doing is telling Interspire Email Marketer to insert two UTM codes (which you designate with the fields that appear there) into each of the hyperlinks inside of your email campaign. Here is an article we published in 2014 that covered this integration between Interspire Email Marketer and Google Analytics:
>>How to track Interspire Email Campaigns with Google Analytics