title: What is the preferred way to filter a regex search for duplicate matches in C#
body: <p>A new question has arisen in relation to an <a href="https://stackoverflow.com/questions/3433774/c-regex-on-a-streamreader-will-not-return-matches">earlier question of mine</a>. I have some code that is using a regex to find email addresses. It's working great except that it returns duplicate matches. I searched this site and found a question from a long time ago that was dealing with a similar problem, and the answer had something to do with mixing the regex logic with a string[] and the Distinct() method. Unfortunately my understanding of arrays is still limited. </p>
  
  <p>My code is placing all the regex matches into a <code>MatchCollection</code>. Aside from that, how do I go about interacting with this <code>MatchCollection</code> to only add unique matches to the regex?</p>