After you have sent the campaign, you will see results in the Mail Merge page. On the list, you will get results for Opens, Clicks and Replies. Click on a line in your list, and you will get more insights. The results page of each Mail Merge will give you results per recipient.
NB: Be sure to use the tool insert link located under your Compose Email window to ensure that your clicked stats are 100% accurate.
You can also see your Mail Merge statistics on your Wizy.io for Gmail dashboard, accessible at the top right of your Gmail