lib/Mailer/MailGun.php
protected function processAttachments(array $attachments)
    {
        $processedAttachments = [];
        $inline = [];
        foreach ($attachments as $attachment) {
            $path = $attachment->getPath();
            $id = $attachment->getId();
            if (isset($id)) {
                // Inline
                $inline[] = $path;
            } else {
                // Attached
                $processedAttachments[$attachment->getName()] = $path;
            }
        }

        return [$processedAttachments, $inline];
    }
protected function processAttachments(array $attachments)
    {
        $processedAttachments = [];
        $inline = [];
        foreach ($attachments as $attachment) {
            $path = $attachment->getPath();
            $id = $attachment->getId();
            if (isset($id)) {
                // Inline
                $inline[] = $path;
            } else {
                // Attached
                $processedAttachments[$attachment->getName()] = $path;
            }
        }

        return [$processedAttachments, $inline];
    }
@param Attachment[] $attachments

@return array First element: An array of attachment paths. Second element: An array of inline paths