Postfix – SMTP Message Rate Control on Ubuntu 8.04

emailpostfixspam

Maybe I am chasing a bug but I am trying to set up a smtp proxy of sorts. I have a postfix server which receives all the email for a collection of servers/clients. It them uses a smarthost (relayhost=…) to forward it's mail to our corporate MTA. I would like to limit the number of messages an individual server can relay to prevent swamping the corporate MTA. Postfix has a program called "anvil" that is capable of tracking stats about mail to be used for such things but it doesn't seem to be executed. I ran "inotifywait -m /usr/lib/postfix/anvil" while I started postfix and sent a number of messages through it from a remote server. inotifywait indicated anvil was never run. Anyone gotten postfix/anvil rate controls to work?

main.cf

smtpd_banner = $myhostname ESMTP $mail_name (Ubuntu)
biff = no
append_dot_mydomain = no
readme_directory = no
myhostname = site-server-q9
alias_maps = hash:/etc/aliases
alias_database = hash:/etc/aliases
myorigin = /etc/mailname
mydestination = localhost
relayhost = Out outgoing mail relay
mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128 10.0.0.0/8
mailbox_size_limit = 0
recipient_delimiter = +
inet_interfaces = 10.X.X.X
smtpd_client_message_rate_limit = 1
anvil_rate_time_unit = 1h

master.cf extract

anvil     unix  -       -       -       -       1       anvil
smtp      inet  n       -       -       -       -       smtpd

Best Answer

In the end I used policyd which does just this sort of thing. I configured it to limit a single IP address to no more than 10000 messages an hour and 1 GB. Below is a copy of the doc a wrote up for myself in case anyone finds it helpful.

Configuring postfix and policyd

After the packages have been installed make the following changes to their configurations. In /etc/postfix/main.cf add the following line

smtpd_client_restrictions = check_policy_service inet:127.0.0.1:10031

In /etc/postfix-policyd.conf

  • change WHITELISTING=1 to WHITELISTING=0
  • change GREYLISTING=1 to GREYLISTING=0
  • change SENDERTHROTTLE=0 to SENDERTHROTTLE=1
  • change QUOTA_EXCEEDED_TEMP_REJECT=1 to QUOTA_EXCEEDED_TEMP_REJECT=0
  • change SENDER_QUOTA_REJECTION="Quota Exceeded." to SENDER_QUOTA_REJECTION="Quota Exceeded, 10,000 messages/hour max!"
  • change SENDER_SIZE_REJECTION="Message size too big." to SENDER_SIZE_REJECTION="Message size too big. 10Mb per message or 1 Gb/hour max!"
  • change SENDERMSGLIMIT=512 to SENDERMSGLIMIT=10000
  • change SENDERRCPTLIMIT=3600 to SENDERRCPTLIMIT=10000
  • change SENDERQUOTALIMIT=250000000 to SENDERQUOTALIMIT=1000000000
  • change SENDERMSGSIZE=10240000 to SENDERMSGSIZE=50000000
  • change SENDER_INACTIVE_EXPIRE=31d to SENDER_INACTIVE_EXPIRE=1h
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