In article <cf0b307a-c83a-4ff9-bc03-9de28362d...@bluepopcorn.net> you write: >The issue isn’t the existing use of HELO names, it’s how they could >be (mis-)used. The fact that a message sender can put anything there >makes HELO basically meaningless.
This is DMARC -- the HELO domain has to match the header From: and there has to be an SPF record that validates it. The most plausible case is that it's a bounce messsage From: mailer-dae...@mta27.foo.bar.example.com the MAIL FROM is null, HELO is mta27.foo.bar.example.com, and the SPF record for mta27.foo.bar.com says that IP is OK. I don't feel strongly about whether to use the HELO name but it doesn't break anything. R's, John _______________________________________________ dmarc mailing list dmarc@ietf.org https://www.ietf.org/mailman/listinfo/dmarc