Tracking traffic by newsletters


We use one platform to sent newsletter. This platform add Google Analytics parameters in links on Newsletter.
We have a Image tracker of piwik to tracking email openings this url pageview is Newsletters/…
We install the AdvancedCampaignReporting plugin anyway the number of visits by campaing is different in piwik and GA.
The link on Newsletter redirect to site and the url pageview is Site/… we have a piwik segment only for pageviews with url contains Site/
Is possible that piwik don´t consider a visit by campaing on segment Site/ because have one pageview previous in other segment?

Best Regards,