If PDF invoices are not arriving with your order emails, check these common causes:

1. Email Trigger Setting: Check WooCommerce → Settings → PDF Smart Receipts → Emails and ensure the checkbox for your specific email status (e.g. Completed Order) is checked.
2. Attachment File Size: Ensure your store logo is compressed (under 1 MB). Extremely large images can delay PDF generation.
3. SMTP Configuration: Ensure your transactional email provider (e.g. WP Mail SMTP, Mailjet) allows attachments up to 5 MB.