search for: smtpd_client_connection_rate_limit

I wanted to pass this along. I'm sure it may be nothing new to most of you, but it has greatly reduced sasl attacks and spam. I found most of it here: https://scottlinux.com/2011/05/26/prevent-postfix-brute-force/ I added the fail2ban rule and modified my postfix main.cf as follows: smtpd_client_connection_rate_limit = 3 smtpd_delay_reject = yes smtpd_helo_required = yes smtpd_helo_restrictions = permit_mynetworks, reject_non_fqdn_helo_hostname, reject_invalid_helo_hostname, permit smtpd_sender_restrictions = permit_mynetworks, reject_non_fqdn_sender, reject_unknown_sender_domain,...

...ender_restrictions= -o smtpd_recipient_restrictions=permit_mynetworks,reject -o mynetworks=127.0.0.0/8 -o strict_rfc821_envelopes=yes -o smtpd_error_sleep_time=0 -o smtpd_soft_error_limit=1001 -o smtpd_hard_error_limit=1000 -o smtpd_client_connection_count_limit=0 -o smtpd_client_connection_rate_limit=0 -o receive_override_options=no_header_body_checks,no_unknown_recipient_checks I have also attached amavisd.conf file with this email. Thanks & Regards Ankush Grover -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.centos.org/pipermail/ce...

...ipient_restrictions=permit_mynetworks,reject > -o mynetworks= 127.0.0.0/8 > -o strict_rfc821_envelopes=yes > -o smtpd_error_sleep_time=0 > -o smtpd_soft_error_limit=1001 > -o smtpd_hard_error_limit=1000 > -o smtpd_client_connection_count_limit=0 > -o smtpd_client_connection_rate_limit=0 > -o > receive_override_options=no_header_body_checks,no_unknown_recipient_checks > > > I have also attached amavisd.conf file with this email. > > Thanks & Regards > > Ankush Grover > > -------------- next part -------------- An HTML attachment was scrubb...

On 26 Nov 2018, at 13.16, Mart Pirita <sysadmin at e-positive.ee> wrote: > > Hi, > > Auth process is not constantly being shutdown and/or restarted and Dovecot is used for SMTP authentication (Postfix). > > Checked few servers logs, they are running v2.3.3, for example latest > (some day none, some day a lot, some day few) logs: > > Nov 25 18:48:11 server1

Hope to get some attention about this idea to reduce hacking passwords. Here is a list of about 700,000 IP addresses that are hacking passwords through SMTP AUTH http://ipadmin.junkemailfilter.com/auth-hack.txt This is a list of IP addresses that attempted to authenticate against my fake AUTH advertizing on servers with no authentication. We do front end spam filtering for thousands of

Dear CentOS Community Is totally clear there's no support sendmail platform today, but I need to stop SMTP brute-force attack on sendmail. My server is attacked today, my maillog look like : 4624 at myserver.com>, proto=ESMTP, daemon=MTA, relay=myserver.com [127.0.0.1] Jun 14 19:07:01 at6412 sendmail[24627]: q5EN71jC024627: from=<>, size=3958, class=0, nrcpts=1,

...s_verify_cert_match = hostname smtp_use_tls = no smtp_xforward_timeout = 300s smtpd_authorized_verp_clients = $authorized_verp_clients smtpd_authorized_xclient_hosts = smtpd_authorized_xforward_hosts = smtpd_banner = $myhostname ESMTP $mail_name (Debian/GNU) smtpd_client_connection_count_limit = 50 smtpd_client_connection_rate_limit = 0 smtpd_client_event_limit_exceptions = ${smtpd_client_connection_limit_exceptions:$mynetworks} smtpd_client_message_rate_limit = 0 smtpd_client_new_tls_session_rate_limit = 0 smtpd_client_recipient_rate_limit = 0 smtpd_client_restrictions = smtpd_data_restrictions = smtpd_delay_open_until_valid...

...reject_unauth_pipelining -o smtpd_end_of_data_restrictions= -o smtpd_restriction_classes= -o mynetworks=127.0.0.0/8,[::1]/128 -o smtpd_error_sleep_time=0 -o smtpd_soft_error_limit=1001 -o smtpd_hard_error_limit=1000 -o smtpd_client_connection_count_limit=0 -o smtpd_client_connection_rate_limit=0 -o receive_override_options=no_header_body_checks,no_unknown_recipient_checks,no_milters -o local_header_rewrite_clients= -o smtpd_milters= -o local_recipient_maps= -o relay_recipient_maps= dovecot unix - n n - - pipe flags=DRhu use...

...tpd_recipient_restrictions=permit_mynetworks,reject -o mynetworks_style=host -o mynetworks=127.0.0.0/8 -o strict_rfc821_envelopes=yes -o smtpd_error_sleep_time=0 -o smtpd_soft_error_limit=1001 -o smtpd_hard_error_limit=1000 -o smtpd_client_connection_count_limit=0 -o smtpd_client_connection_rate_limit=0 -o receive_override_options=no_header_body_checks,no_unknown_recipient_checks -o smtpd_data_restrictions=reject_unauth_pipelining -o smtpd_end_of_data_restrictions= dovecot unix - n n - - pipe flags=DRhu user=www-data:www-data argv=/usr/lib/dovecot/...

...= no smtp_xforward_timeout = 300s smtpd_authorized_verp_clients = $authorized_verp_clients smtpd_authorized_xclient_hosts = smtpd_authorized_xforward_hosts = smtpd_banner = $myhostname ESMTP $mail_name smtpd_client_connection_count_limit = 50 smtpd_client_connection_limit_exceptions = $mynetworks smtpd_client_connection_rate_limit = 0 smtpd_client_restrictions = smtpd_data_restrictions = smtpd_delay_reject = yes smtpd_enforce_tls = no smtpd_error_sleep_time = 1s smtpd_etrn_restrictions = smtpd_expansion_filter = \t\40!"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`abcdefghijklmnopqrstuv...

HI, > You could set > > syslog_facility = local5 > > and have all the log messages in the messages file. According to the output of command # doveadm log find every type of message goes to the file I was looking at, "/var/spool/maillog". >> So, is it postfix doing the local mail delivery, not dovecot? >> > To answer this question please post relevant

..._timeout = 3600s smtp_tls_verify_cert_match = hostname smtp_use_tls = no smtp_xforward_timeout = 300s smtpd_authorized_verp_clients = $authorized_verp_clients smtpd_authorized_xclient_hosts = smtpd_authorized_xforward_hosts = smtpd_banner = $myhostname ESMTP smtpd_client_connection_count_limit = 50 smtpd_client_connection_rate_limit = 0 smtpd_client_event_limit_exceptions = ${smtpd_client_connection_limit_exceptions:$mynetworks} smtpd_client_message_rate_limit = 0 smtpd_client_new_tls_session_rate_limit = 0 smtpd_client_port_logging = no smtpd_client_recipient_rate_limit = 0 smtpd_client_restrictions = smtpd_command_filter =...

...st_anchor_file = smtp_tls_verify_cert_match = hostname smtp_use_tls = no smtp_xforward_timeout = 300s smtpd_authorized_verp_clients = $authorized_verp_clients smtpd_authorized_xclient_hosts = smtpd_authorized_xforward_hosts = smtpd_banner = $myhostname ESMTP smtpd_client_connection_count_limit = 50 smtpd_client_connection_rate_limit = 0 smtpd_client_event_limit_exceptions = ${smtpd_client_connection_limit_exceptions:$mynetworks} smtpd_client_message_rate_limit = 0 smtpd_client_new_tls_session_rate_limit = 0 smtpd_client_port_logging = no smtpd_client_recipient_rate_limit = 0 smtpd_client_restrictions = smtpd_command_filter = s...

...3600s smtp_tls_verify_cert_match = hostname smtp_use_tls = no smtp_xforward_timeout = 300s smtpd_authorized_verp_clients = $authorized_verp_clients smtpd_authorized_xclient_hosts = smtpd_authorized_xforward_hosts = smtpd_banner = $myhostname ESMTP $mail_name smtpd_client_connection_count_limit = 50 smtpd_client_connection_rate_limit = 0 smtpd_client_event_limit_exceptions = ${smtpd_client_connection_limit_exceptions:$mynetworks} smtpd_client_message_rate_limit = 0 smtpd_client_new_tls_session_rate_limit = 0 smtpd_client_port_logging = no smtpd_client_recipient_rate_limit = 0 smtpd_client_restrictions = smtpd_command_filter = s...