They are already enabled by default for each email, so you don't need to worry in that regard.
To view the data about the email channel in general, go to ACQUISITION — All Traffic — Channels
To track separate the effectiveness of promo and trigger campaigns, go to the Email channel.
Select Other — Acquisition — Traffic Sources — Source
To evaluate the performance of each separate mailing or a separate trigger-mail, go to eSputnik-promo or eSputnik-trigger
In the opened tab select Source — Other — Acquisition — Campaign.
You will be shown the names of the mailings that you sent and their’s data.
You can create a series of emails, combine them by one tag and thus track the effectiveness of a series of emails in general.
First, put a mark on the emails you need.
The data will be shown in Google Analytics in: Acquisition — Keyword report.
Now you can view the data and assess the effectiveness of email series campaigns.