Adding Google UTM Tracking Parameters To Email Campaigns
A UTM tag is a tracking marker appended to a URL, and is recognised by Google Analytics.
By default UTM_Campaign and UTM_Content can be set in the campaign edit screen shown below.
If the UTM_Campaign property is not set then it will be set with the name of the campaign as shown in the Campaign Name property.
You can also add further parameters by clicking on the "more tracking params?" link