Why Does Politico Think I am Not Reading their News-Letters?

Hi All: Several weeks ago Politico wrote-and-said because I am not opening 
their mailings, they are going to free up space in my inbox. Well, yes, because 
all Politico news-letters are much easier reading as html, I open them from 
Alpine through Lynx. When I view an html file this way, am I reading it 
internally or actually visit politico.com?
So we subscribed again to several of these, but this seems to happen from 
time2time. Many times I click through article or video links, so how can they 
say I am not opening their news-letters? Thanks so much in advance for your 
analysis.
Chime