732
732
<a href="smtpd.8.html">smtpd(8)</a> processes. Its purpose is to accept connections from the
733
733
network and to decide what SMTP clients are allowed to talk to
734
734
Postfix. According to the 2008 MessageLabs annual report, 81% of
735
all email was spam, and 90% of that was sent by botnets. While
736
<a href="postscreen.8.html">postscreen(8)</a> keeps the zombies away, more <a href="smtpd.8.html">smtpd(8)</a> processes remain
737
available for legitimate clients. </p>
735
all email was spam, and 90% of that was sent by botnets; by 2010,
736
those numbers were 92% and 95%, respectively. While <a href="postscreen.8.html">postscreen(8)</a>
737
keeps the zombies away, more <a href="smtpd.8.html">smtpd(8)</a> processes remain available
738
for legitimate clients. </p>
739
<p> The <a href="postscreen.8.html">postscreen(8)</a> server is still evolving, and is likely to
740
undergo changes that break compatibility with earlier versions.
741
For this reason the <a href="postscreen.8.html">postscreen(8)</a> server is not installed with the
742
stable Postfix release. </p>
740
<p> The <a href="postscreen.8.html">postscreen(8)</a> server is available with Postfix 2.8 and
741
later. To keep the implementation simple, <a href="postscreen.8.html">postscreen(8)</a> delegates
742
DNS white/backlist lookups to <a href="dnsblog.8.html">dnsblog(8)</a> server processes, and
743
delegates TLS encryption/decryption to <a href="tlsproxy.8.html">tlsproxy(8)</a> server processes.
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This delegation is invisible to the remote SMTP client, and is not
745
shown in the diagram below. </p>
added
removed
html/OVERVIEW.html
