Hi Ludi.
One option might be to add OpenDMARC to your implementation? The reason
for mentioning this is because in addition to checking DMARC policies,
OpenDMARC also has an option to reject any message that doesn't have the
mandatory headers according to RFC 5322:
/RequiredHeaders (Boolean)/
If set, the filter will ensure the header of the message conforms to the
basic header field count restrictions laid out in RFC5322, Section 3.6.
Messages failing this test are rejected without further processing. A
From: field from which no domain name could be extracted will also be
rejected.
If I understand the RFC correctly this includes the Date and From headers.
Nick.
On 26/12/20 6:58 am, ludic...@gmail.com wrote:
Hi,
I am seeing a wave of MS Azure Cloud Spam these days.
Many of these mails come with a header:
* Return-Path: <MAILER-DAEMON>
* Empty From Field
They than pass the greylisting filter (and all others it seems) with
„Bounce message. Skip.“
Is there a way to influence this behaviour?
Postfix on debian stretch / no Spamassassin.
Greets,
Ludi
