Getting smtp error 554 due to bad reputation of sender

[rf1234]

I am getting error 554 due to bad reputation of sender from some recipients (not all).

That is in spite of the fact that the sender doesn't really have a bad reputation because I can send emails to the same recipient from my own email server which uses all of the following standards DNSSEC, SPF, DKIM and DMARC. I suspect that smtp-validate-email doesn't use all of the standards mentioned above and that this causes the error?!

Can you take a look? What could be done to "upgrade" smtp-validate-email's access to comply with the standards mentioned above?