title: PCRE regex to Re2 Regex without negative lookahead
body: <p>I am trying to use regex to filter emails from certain addresses in my office G Suite account email routing. In order to do so, I have created the following regex in order to do the following:</p>
  
  <ol>
  <li>Accept all email address from a domain "domain.com"</li>
  <li>Reject 2 of all those addresses from that domain.</li>
  </ol>
  
  <p>In order to do so, I created the following regex that will complete the said function:</p>
  
  <pre><code>^(?!test|tes2)[A-Z0-9._%+-]+@domain.com$
  </code></pre>
  
  <p>This one will reject both test@domain.com and tes2@domain.com and accept all other combinations from the said domain.</p>
  
  <p>However, G suite does not accept PCRE regex, so I currently cannot achieve this.</p>
  
  <p>Temporarily, I created the following Re2 regex to accept all email addresses from the said domain:</p>
  
  <pre><code>(\W|^)[\w.+\-]{0,25}@(domain)\.com(\W|$)
  </code></pre>
  
  <p>How can I expand this to allow the functionality intended since lookarounds are not allowed in re2 regex?</p>