Why is delivery of mail generated by CommuniGate Pro mailing lists to Yahoo and Gmail users is failing with the following message in the CGP logs?

421 4.7.0 [XXXX] Message from (XXX.XXX.XXX.XXX) temporarily deferred - XX.XX.XX. Please refer to http://postmaster.yahoo.com/errors/postmaster-21.html

To be compatible with DMARC, please enable the 'Hide From Addresses' setting for the CGP mailing list(s) in question.

https://www.communigate.com/communigatepro/LIST.html#Postings

Preserving the "FROM:" address is not compatible with DMARC.