Gitweb:
https://git.exim.org/exim.git/commitdiff/b307aa8435cd2746e12f0741903814b86f0f3ee9
Commit: b307aa8435cd2746e12f0741903814b86f0f3ee9
Parent: 38a522bdfc23e9a221b475891f954b0dd6f82eee
Author: Jeremy Harris <jgh146exb@???>
AuthorDate: Sat Feb 13 15:16:47 2021 +0000
Committer: Jeremy Harris <jgh146exb@???>
CommitDate: Sat Feb 13 15:16:47 2021 +0000
Docs: more notes on dnslists
---
doc/doc-docbook/spec.xfpt | 15 +++++++++++++++
1 file changed, 15 insertions(+)
diff --git a/doc/doc-docbook/spec.xfpt b/doc/doc-docbook/spec.xfpt
index edba123..782343f 100644
--- a/doc/doc-docbook/spec.xfpt
+++ b/doc/doc-docbook/spec.xfpt
@@ -32496,6 +32496,13 @@ Section &<<SECTaddmatcon>>& below describes how you can distinguish between
different values. Some DNS lists may return more than one address record;
see section &<<SECThanmuldnsrec>>& for details of how they are checked.
+.new
+Values returned by a properly running DBSBL should be in the 127.0.0.0/8
+range. If a DNSBL operator loses control of the domain, lookups on it
+may start returning other addresses. Because of this, Exim now ignores
+returned values outside the 127/8 region.
+.wen
+
.section "Variables set from DNS lists" "SECID204"
.cindex "expansion" "variables, set from DNS list"
@@ -32632,6 +32639,14 @@ deny dnslists = relays.ordb.org
.endd
which is less clear, and harder to maintain.
+Negation can also be used with a bitwise-and restriction.
+The dnslists condition with only be trus if a result is returned
+by the lookup which, anded with the restriction, is all zeroes.
+For example:
+.code
+deny dnslists = zen.spamhaus.org!&0.255.255.0
+.endd
+
