The issue:
Couple of days ago we faced spam attack from external IP that was using a real external domain to send around 7k email to different external domains like yahoo, hotmail, gmail ....etc, that i had to block that ip by the firewall manually,
- How to only allow defined domains in my "domain" mysql database and reject others (even if they were real having MX and A records) like the
reject_unlisted_senderparameter behavior
Configurations:
- /etc/postfix/main.cf
.....
smtpd_sasl_auth_enable = yes
broken_sasl_auth_clients = yes
smtpd_sasl_authenticated_header = yes
smtpd_sender_restrictions = check_sender_access hash:/etc/postfix/sender_access, reject_unlisted_sender, permit_sasl_authenticated, reject_unknown_sender_domain
smtpd_recipient_restrictions = permit_mynetworks, permit_sasl_authenticated, reject_unauth_destination
transport_maps = proxy:mysql:/etc/postfix/mysql-virtual_transports.cf
...........
- /etc/postfix/master.cf
smtp inet n - - - - smtpd
smtps inet n - - - - smtpd
-o syslog_name=postfix/smtps
-o smtpd_tls_wrappermode=yes
-o smtpd_sasl_auth_enable=yes
-o smtpd_client_restrictions=permit_sasl_authenticated,reject
......
127.0.0.1:10025 inet n - - - - smtpd
-o content_filter=
-o local_recipient_maps=
-o relay_recipient_maps=
-o smtpd_restriction_classes=
-o smtpd_client_restrictions=
-o smtpd_helo_restrictions=
-o smtpd_sender_restrictions=
-o smtpd_recipient_restrictions=permit_mynetworks,reject
-o mynetworks=127.0.0.0/8
-o strict_rfc821_envelopes=yes
-o receive_override_options=no_unknown_recipient_checks,no_header_body_checks
# -o smtpd_bind_address=127.0.0.1
Versions:
My mailserver is running on "Ubuntu 12.04, postfix 2.9.6, courier"
