We have the same problem other people has. We have configured properly the application self-hosted SMTP. Our domain has correctly configured SPF, DKIM, DMARC, all test passed viewing the original message with GMAIL. The problem is that, when the PDF is attached by phantomjs service marking the check into invoiceninja, and the PDF is attached, the mail is detected as potencialy dangerous in destination mail account.
If the PDF is not attached, the mail is received in inbox.
Any advice or solution to attach the PDF and going message to inbox?