From a446f8be900b74960b98cb4a994596922088bbf4 Mon Sep 17 00:00:00 2001 From: Stoiko Ivanov Date: Tue, 21 Apr 2020 12:43:31 +0200 Subject: [PATCH] rephrase greylisting section in pmg-intro and mention that the netmask for greylisting is configurable Signed-off-by: Stoiko Ivanov --- pmg-intro.adoc | 21 ++++++++++++--------- 1 file changed, 12 insertions(+), 9 deletions(-) diff --git a/pmg-intro.adoc b/pmg-intro.adoc index e43fd6e..94566c0 100644 --- a/pmg-intro.adoc +++ b/pmg-intro.adoc @@ -87,16 +87,19 @@ in message bodies. Greylisting:: -Greylisting an email from a sender your system does not recognize, -means, that it will be temporarily rejected. Since temporary failures -are built into the RFC specifications for mail delivery, a legitimate -server will try to resend the email later on. This is an effective -method because spammers do not queue and reattempt mail delivery as is -normal for a regular Mail Transport Agent. +Greylisting an email means, that it will be temporarily rejected. Since +temporary failures are part of the the RFC specifications for mail delivery, a +legitimate server will try to resend the email later on. Spammers on the other +hand, do not queue and reattempt mail delivery. A greylisted email never +reaches your mail server and thus your mail server will not send useless "Non +Delivery Reports" to spammers. Additionally greylisted mail is not analyzed +by the antivirus and spamdetector engines, which saves resources. Greylisting +can reduce e-mail traffic up to 50%. + + -Greylisting can reduce e-mail traffic up to 50%. A greylisted email -never reaches your mail server and thus your mail server will not send -useless "Non Delivery Reports" to spammers. +A mail is greylisted if it is the first mail from a sender to a receiver +coming from a particular IP network. You can configure which IP addresses +belong to the same network, by setting an appropriate netmask for greylisting. SMTP Protocol Tests:: -- 2.39.2