On Sun, 7 Aug 2022, Linkcheck wrote:
And now, during the past few days, zen has blocked a couple of valid emails,
the IPs of which zen claims to know nothing about.
Last week zen.spamhaus blocked over 280 emails; I've going to miss it.
I have now removed spamhaus from postfix entirely and hope that spamassassin
will catch any nasties. It will be interesting to see if any valid emails get
trapped by SA.
For reference, a couple of samples of the blocked emails are:
[...]
Now at least you know that the problem is that Spamhaus is returning
127.255.255.254 (blocking your DNS resolver), while at the same time you
have/had postfix wrongly configured, in view of your e-mail of Aug 3rd, from
which it looks like you are not using the recommended set-up, and are thus
rejecting based on return codes which do not mean that the IP address is
blacklisted.
You should read:
https://www.spamhaus.org/news/article/788/spamhaus-dnsbl-return-codes-technical-update.
and
https://docs.spamhaus.com/datasets/docs/source/40-real-world-usage/PublicMirrors/MTAs/020-Postfix.html
Cheers.
