diff --git a/pmg-intro.adoc b/pmg-intro.adoc
index 6a44396..7d90e41 100644
--- a/pmg-intro.adoc
+++ b/pmg-intro.adoc
@@ -51,7 +51,7 @@ lists of addresses linked to spamming.
 SMTP Whitelist::
 
 Exclude senders from SMTP blocking. To prevent all SMTP checks
-(Greylisting, Receiver Verification, SPF and RBL) and accept all
+(Greylisting, Receiver Verification, SPF and DNSBL) and accept all
 e-mails for the analysis in the filter rule system, you can add the
 following to this list: Domains (Sender/Receiver), Mail address
 (Sender/Receiver), Regular Expression (Sender/Receiver), IP address
diff --git a/pmgconfig.adoc b/pmgconfig.adoc
index f1236f1..73c4cf8 100644
--- a/pmgconfig.adoc
+++ b/pmgconfig.adoc
@@ -582,11 +582,16 @@ ifndef::manvolnum[]
 endif::manvolnum[]
 
 All SMTP checks are disabled for those entries (e.g. Greylisting,
-SPF, RBL, ...)
+SPF, DNSBL, ...)
+
+DNSBL checks are done by `postscreen` which works on IP addresses and networks.
+This means it can only make use of the `IP Address` and `IP Network` entries.
 
 NOTE: If you use a backup MX server (e.g. your ISP offers this service
 for you) you should always add those servers here.
 
+NOTE: To disable DNSBL checks entirely, remove any `DNSBL Sites` entries in
+xref:pmgconfig_mailproxy_options[Mail Proxy Options].
 
 [[pmgconfig_spamdetector]]
 Spam Detector Configuration