title: Powermail 4.4.0 - performance issues while editing records in backend
body: <p>i have a specific problem regarding editing mail records in TYPO3 backend.
  When you select a mail record via <strong>List module > 'folder' > Mails 'record'</strong> it takes a very long time for the contents to show.</p>
  
  <p>I figured that it has something to do with the high number of the stored records (>12.000 mail records &amp; >140.000 answer records).</p>
  
  <p>Is there a way to create a more performant query ?
  My thought of a solution was to maybe override certain field TCAs, but until now i wasn't able to adjust the query to fit my needs.</p>
  
  <p>Thanks and regards.</p>
  
  <p>System:
  TYPO3 7.6.25
  Powermail 4.4.0</p>