src/Model/Email.php
public function getComputedAttachments(): array
    {
        if (! $this->hasAttachments()) {
            return [];
        }
        $attachments = $this->getAttachments();

        // Process the attachments dir if any, and include the files in that folder
        $dir = $this->getAttachmentsDir();
        $path = $dir['path'] ?? null;
        $recursive = $dir['recursive'] ?? false;

        if (is_string($path) && is_dir($path)) {
            $files = $recursive ? new RecursiveIteratorIterator(
                new RecursiveDirectoryIterator($path, RecursiveDirectoryIterator::SKIP_DOTS),
                RecursiveIteratorIterator::CHILD_FIRST
            ) : new DirectoryIterator($path);

            /* @var \SplFileInfo $fileInfo */
            foreach ($files as $fileInfo) {
                if ($fileInfo->isDir()) {
                    continue;
                }
                $attachments[] = $fileInfo->getPathname();
            }
        }

        return $attachments;
    }
public function getComputedAttachments(): array
    {
        if (! $this->hasAttachments()) {
            return [];
        }
        $attachments = $this->getAttachments();

        // Process the attachments dir if any, and include the files in that folder
        $dir = $this->getAttachmentsDir();
        $path = $dir['path'] ?? null;
        $recursive = $dir['recursive'] ?? false;

        if (is_string($path) && is_dir($path)) {
            $files = $recursive ? new RecursiveIteratorIterator(
                new RecursiveDirectoryIterator($path, RecursiveDirectoryIterator::SKIP_DOTS),
                RecursiveIteratorIterator::CHILD_FIRST
            ) : new DirectoryIterator($path);

            /* @var \SplFileInfo $fileInfo */
            foreach ($files as $fileInfo) {
                if ($fileInfo->isDir()) {
                    continue;
                }
                $attachments[] = $fileInfo->getPathname();
            }
        }

        return $attachments;
    }
Processes the attachments dir and merges the result with the attachments array, then returns the result

@return array