The first question would be, which software are you using. With that
said, most email software allows you to highlight the emails in question
and you can click and drag them to the folder that you desire, thus
moving them from the sent folder. Here is another question, are you
trying to move them to a .pst folder. like in Outlook? If so, then this
is quite an easy operation with the click and drag. Once you move it,
it should no longer be in the sent folder. So, please let us know what
is the email software that you are using. Thanks.