A few of our customers have been reporting not receiving some of the emails sent from our ERP (NetSuite) and they are not even in their spam folder. It shows correctly being sent on our side.
We have set up DKIM, SPF, and DMARC records for netsuite and mainly don't have issues. Websites like mxtoolbox show no issues. Emails sent are correctly signed by our domain, and our dmarc reports show dmarc compliance with our netsuite and gmail traffic.
Although, and this is the only feedback we are working with at the moment, mail-tester.com gives us a really bad score (4.4) and says "Your message failed the DMARC verification" and "mail-tester.com; dkim=fail reason="signature verification failed" (1024-bit key; unprotected)"
Any ideas on how to troubleshoot what may be wrong with our DNS settings?