Yes, we have all DNS settings configured correctly. We use big email provider to send emails (Gmail & fastmail). We send order emails via smtp client.

We already did try to figure out why our emails are marked as spam including external help and available support channels and do follow all known good practices.

I'm not looking for advice on how to make my email not look like spam to their systems. Please assume for the sake of the quotation that we did due diligence here.

I'm really asking if there is a precedence for someone trying to sue big company for damages caused by their refusal to not mark legit emails as spam.