src/MimeMailer/SpoolManager.php
public function setSpoolDirectory($dir)
    {
        if (!DirectoryHelper::ensureExists($dir)) {
            throw new \Exception(
                sprintf('Can not create emails spooling directory "%s"!', $dir)
            );
        }
        $this->spool_dir = $dir;
        return $this;
    }
public function setSpoolDirectory($dir)
    {
        if (!DirectoryHelper::ensureExists($dir)) {
            throw new \Exception(
                sprintf('Can not create emails spooling directory "%s"!', $dir)
            );
        }
        $this->spool_dir = $dir;
        return $this;
    }
Set the spooled mails directory

@param string $dir The directory where to create spooled mails files
@return self
@throws \Exception if the directory doesn't exist and can't be created
@see \Library\Helper\Directory::ensureExists()