vthrottle is an implementation of an SMTP throttling engine for Sendmail servers, based upon M. Williamson's mechanisms, as described in his 2003 Usenix Security paper. It allows the administrator to control how much email users and hosts may send, hindering the rapid spread of viruses, worms, and spam. Exceptions can be made using a whitelist mechanism, which can be generated manually or with the included tool "vmeasure". vthrottle tells the misbehaving client to hold on to the deferred mail and resend it at a later time.
Re: vthrottle EOL
> sendmail 8.13 is currently in beta and
> includes a mechanism to vthrottle to
> control mail rates.
that should read "a mechanism similar to vthrottle ..."
really, my grammar isn't THAT bad :)
sendmail 8.13 is currently in beta and includes a mechanism to vthrottle to control mail rates. because this is built-in to future versions of sendmail, vthrottle is marked for EOL when 8.13 comes out. this will give people a portable, supported mechanism to control their mail with the same goals as vthrottle. vthrottle will probably never be ported to other systems like Linux or solaris, therefore. however, until 8.13 is released i'll keep playing with it.
i'm excited to see sendmail doing this.
postfix users may want to look at the anvil tool in new postfix versions, it does similar mail control.
thanks for your interest in vthrottle.