Am 17.10.2015 um 09:45 schrieb Jayesh Shinde:
> Hello all  ,
> 
> I am having mailserver with centos 6.3 + cyrus-imad + postfix + ldap
> 
> Many spammer are trying to hack password for doing many authentication 
> with pop3 + imap + smtp  services.
> on server Fail2ban has been  added , but its blocking hacker IPs after
> certain interval  and not in real time.  Which is the actual issue.
> 
> I am looking for some real-time blocking where that particular  spammer
> IP + email id must get block  .
> 
> I believe this issue is very common with other too ,  is there any
> option in 'saslauthd'  /  postfix  / cyrus-imapd for below requirement ?
> 
> 1)  If server receive the wrong password , then is it possible to
> introduce the delay of say 5-10 seconds to sender client ? So that
> spammer will do less attempt ?
> 2)  After given wrong password attempt more than 3 time , the particular
> "IP + email id" must get block for next 5-10 min.
> And then need to unblock after  that. 
> 3) I check PAM-ABL , but its not working for 'saslauthd'' with pop /
> imap / smtp . Because I came to know that 'saslauthd'' is not getting IP
> of source . 
> How to pass  source IP to "saslauthd''  along with email id , password
> and relam .  Is there any patch available for this ?
> 
> 
> Please suggest
> 
> Regards
> Jayesh Shinde

perhaps you wanna poke with this

https://sys4.de/de/blog/2014/03/27/fighting-smtp-auth-brute-force-attacks/

https://sys4.de/de/blog/2012/12/28/botnets-mit-rsyslog-und-iptables-recent-modul-abwehren/

http://blog.schaal-24.de/firewall/postfix-postscreen-ip-in-die-firewall-eintragen/

Best Regards
MfG Robert Schetterer

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