lib/classes/Swift/Mime/MimePart.php
public function setDelSp($delsp = true)
    {
        $this->setHeaderParameter('Content-Type', 'delsp', $delsp ? 'yes' : null);
        $this->userDelSp = $delsp;

        return $this;
    }
public function setDelSp($delsp = true)
    {
        $this->setHeaderParameter('Content-Type', 'delsp', $delsp ? 'yes' : null);
        $this->userDelSp = $delsp;

        return $this;
    }
public function setDelSp ( $ delsp = true ) { $ this -> setHeaderParameter ( 'Content-Type' , 'delsp' , $ delsp ? 'yes' : null ) ; $ this -> userDelSp = $ delsp ; return $ this ; }
Turn delsp on or off for this entity.

@param bool $delsp

@return $this
Turn delsp on or off for this entity .