src/Mail/Message.php
public function addEmbeddedFile(string $file, string $content = null, string $contentType = null): MimePart
    {
        return $this->inlines[$file] = $this->createAttachment($file, $content, $contentType, 'inline')
            ->setHeader('Content-ID', $this->getRandomId());
    }
public function addEmbeddedFile(string $file, string $content = null, string $contentType = null): MimePart
    {
        return $this->inlines[$file] = $this->createAttachment($file, $content, $contentType, 'inline')
            ->setHeader('Content-ID', $this->getRandomId());
    }
public function addEmbeddedFile ( string $ file , string $ content = null , string $ contentType = null ) : MimePart { return $ this -> inlines [ $ file ] = $ this -> createAttachment ( $ file , $ content , $ contentType , 'inline' ) -> setHeader ( 'Content-ID' , $ this -> getRandomId ( ) ) ; }
Adds embedded file.

@param string      $file
@param string|null $content
@param string|null $contentType

@return MimePart
Adds embedded file .