title: Remove entire line from csv if matches a string from within a txt file
body: <p>I have a csv formatted like:</p>
  
  <pre><code>Username,Email,Fn,Ln,BusUnit,Department,Manager
  USER1@domain.COM,USER1@domain.com,USER1,Ops,Whse,"""MGR1"""
  USER2@domain.COM,USER2@domain.com,USER2,Proc,Acct,"""MGR2""
  </code></pre>
  
  <p>I have a txt file formatted like:</p>
  
  <pre><code>USER1@domain.COM
  USER2@domain.COM
  </code></pre>
  
  <p>I would like to remove all lines in the CSV unless they match on any of the emails in the txt file.</p>
  
  <p>This is clearly incorrect, but it's what I have so far</p>
  
  <pre><code>$users = import-csv .\user.csv
  $unresolved = gc .\unresolved.txt
  
  get-content $users |? {$_ -match $unsresolved} |export-csv export.csv -notype
  </code></pre>