Description of problem:
  We need to implement Sendmail's rate throttling module to automatically
  reject hosts which get infected by viruses or spambots. Sendmail does
  provide for this in the form of the 'ratecontrol' and 'conncontrol'
  modules but they are not working.

  Documentation on these modules is available in /usr/share/sendmail-cf/README


Version-Release number of selected component (if applicable):
  8.13.1-3.RHEL4.5


How reproducible:
  Always


Steps to Reproduce:
  1. Add lines to /etc/mail/sendmail.mc (after 'FEATURE(access_db):
    dnl # Limit machines sending viruses
    define(`confCONNECTION_RATE_WINDOW_SIZE', `600s')dnl
    FEATURE(`greet_pause', `2000')dnl
    FEATURE(`ratecontrol')dnl
    FEATURE(`conncontrol')dnl
  2. Add lines to /etc/mail/access:
    GreetPause:127.0.0.1     0
    ClientConn:127.0.0.1     0
    ClientConn:10.0          5
    ClientConn:192.168       5
    ClientConn:              50
    ClientRate:127.0.0.1     0
    ClientRate:10.0          10
    ClientRate:192.168       10
    ClientRate:              100
  3. Rebuild configuration files and restart sendmail:
    make -C/etc/mail
    m4 /etc/mail/sendmail.mc > /etc/mail/sendmail.cf
    service sendmail restart

  
Actual results:
  We've unfortunately just been blacklisted due to a user's machine being
  infected by a spambot which sent out over 16,000 messages over a two hour
  window.


Expected results:
  The configuration above should automatically limit clients when sending
  more than 10 emails within 600 seconds (10 minutes) when the connection
  originates from the 192.168.0.0/16 or 10.0.0.0/16 subnets.



Additional info: