Best defense against this?

7 msg	Postfix 2.2.5 on latest Solaris 9 x86
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12 msg	Newb Question

Best defense against this?
\ Justin Piszcz (23 Sep 2007)
. \ Ralf Hildebrandt (23 Sep 2007)
. . \ Justin Piszcz (23 Sep 2007)
. . . \ Ralf Hildebrandt (23 Sep 2007)
. . . . \ Justin Piszcz (23 Sep 2007)
. \ Marcel de Reuver (23 Sep 2007)
. . \ Glenn Matthys - OpenGate (23 Sep 2007)
. . . \ Justin Piszcz (23 Sep 2007)
. . . . \ mouss (23 Sep 2007)
. \ Felix J. Ogris (23 Sep 2007)
. \ Marcel de Reuver (23 Sep 2007)
. . \ Tony Earnshaw (23 Sep 2007)
. . . \ Victor Duchovni (23 Sep 2007)

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Subject:	Best defense against this?
Group:	Postfix-users
From:	Justin Piszcz
Date:	23 Sep 2007

Hello,

I was wondering what is the best defense against this?

One could use fail2ban but then it can possibly reject legitimate e-mail
servers if they have multiple 'lost connections' as well.

I suppose decreasing the smtpd time will help but its already set to 60.

Sep 22 18:00:33 l2 postfix/smtpd[25160]: connect from
ebo92.internetdsl.tpnet.pl[83.14.144.92]
Sep 22 18:00:33 l2 postfix/smtpd[25160]: lost connection after CONNECT
from ebo92.internetdsl.tpnet.pl[83.14.144.92]
Sep 22 18:00:33 l2 postfix/smtpd[25160]: disconnect from
ebo92.internetdsl.tpnet.pl[83.14.144.92]
Sep 22 18:02:33 l2 postfix/smtpd[26212]: connect from
ebo92.internetdsl.tpnet.pl[83.14.144.92]
Sep 22 18:02:34 l2 postfix/smtpd[26212]: lost connection after CONNECT
from ebo92.internetdsl.tpnet.pl[83.14.144.92]
Sep 22 18:02:34 l2 postfix/smtpd[26212]: disconnect from
ebo92.internetdsl.tpnet.pl[83.14.144.92]
Sep 22 18:04:39 l2 postfix/smtpd[26214]: connect from
ebo92.internetdsl.tpnet.pl[83.14.144.92]
Sep 22 18:04:40 l2 postfix/smtpd[26214]: lost connection after CONNECT
from ebo92.internetdsl.tpnet.pl[83.14.144.92]
Sep 22 18:04:40 l2 postfix/smtpd[26214]: disconnect from
ebo92.internetdsl.tpnet.pl[83.14.144.92]

Justin.