title: postfix and save to sent mail dir
body: <p>i know this might be  a dummy question or a question that comes from lake of knowledge, but i hope someone can still answer it. i did try to read a lot of postfix documentation but found no answer to this. i don't even know if it's a postfix specific or mail servers general question. </p>
  
  <p>so i have a mail server, just a clean postfix install that delivers email.
  iv'e defined my users and connected with IMAP and SMTP using thunderbird. </p>
  
  <p>when i went to thunderbird account settings and disabled "place a copy", postfix did not put a copy of the sent message in the user .Sent folder. </p>
  
  <p>however, iv'e also connected my gmail,hotmail or yahoo mail and diabled the "place a copy" and still have a copy in the sent items folder. </p>
  
  <p>so in this case there are 2 options:</p>
  
  <ol>
  <li>something is wrong with my postfix configuration</li>
  <li>gmail,hotmail,yahoo put a copy in thier sent folder as a different process on the server side</li>
  </ol>
  
  <p>thanks in advance</p>