greylisting: wording and drop dubious 50% number

best viewed with
git show --word-diff=color

I mean possibly it was inteded to be marketing speach, but it's not
really relatable where it comes from; and we mention reduced load and
such already

Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>

diff --git a/pmg-intro.adoc b/pmg-intro.adoc
index 94566c055736e6c63fd684d2deb18f56b016fba9..664c0306b00624754cc7bfed930ca5c4d969958b 100644 (file)
--- a/pmg-intro.adoc
+++ b/pmg-intro.adoc
@@ -87,14 +87,13 @@ in message bodies.
 
 Greylisting::
 
-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 an email means that unknown senders are intentionally temporarily
+rejected. Since temporary failures are part of the 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 spam-detector engines, which saves resources.
 
 +
 A mail is greylisted if it is the first mail from a sender to a receiver