On 18 Nov 2019, at 05:22, Gregory Heytings <g...@sdf.org> wrote: >> Is it safe (or mostly safe) to simply block attempts to deliver mail with a >> helo that is only an IP address? (I am talking about only on postfix/stmpd >> and obviously not on postfix/submit or related). >> > > No it is not, it's a RFC violation.
I know it’s an RFC violation, but I see no email that is delivered with a bare IP helo that is legitimate. And I reject TFC compliant mails all the time. In fact, the vast majority of mail that is attempted on my server is RFC compliant and rejected. > The string that follows HELO/EHLO is purely informational, it should not be > used for any filtering purpose. If you use it for this, you'll end up > rejecting legitimate emails. How much legitimate mail do you get with an IP helo? -- "Love is the triumph of imagination over intelligence." - H. L. Mencken
