On Tue, 2003-09-23 at 22:56, Rob Chanter wrote: > On Sat, Sep 20, 2003 at 09:30:27AM -0400, Steven W. Orr wrote: > [snip] > You can block mail at (basically) four points during mail reception: > > * During the HELO/EHLO > * During or after you receive envelope information > * At the *end* of data but before you have decided to accept the message > and sent a 250 return code to the client > * After you have accepted the mail but before its next hop (either > delivery to a mailbox or relay to another server) > > The first 3 of those stages you can send a 5xx return code and the sender > knows right there that you rejected the message. In the last case, you > have to generate a bounce to the envelope sender, which in the case of > most spam and email-borne viruses will be forged. So you'd prefer to > reject unwanted mail as early as possible in the SMTP transaction. > > There's not, for practical purposes, any way to cut off a message in the > middle of the DATA stage, which is what you seem to want to do. Having > given the client the OK to send data, it'll just send the whole lot down > your pipe and wait for an answer. I don't know about milter, but in the > case of postfix, body checks are enforced at the *end* of data and > content filters generate bounces. > > With SA, you have to receive the whole message to make any sense of it, > so you basically can't hope to save bandwidth based on anything you spot > in the message contents. > > Everyone uses SA by piping it through something, be it procmail, > amavis, milter, or something else entirely. Something has to read and > act on the data SA adds to the message. I'm oversimplifying a bit, but > not much.
There's an app in the Debian tree named Mailfilter. (They just package it, so Google should find it.) <DESCRIPTION> Description: A program that filters your incoming e-mail to help remove spam. Mailfilter is very flexible utility for UNIX (-like) operating systems to get rid of unwanted e-mail messages, before having to go through the trouble of downloading them to the local computer. It offers support for one or many POP3 accounts and is especially useful for dialup connections via modem, ISDN, etc. Install Mail- filter if you'd like to remove spam from your POP3 mail accounts. . With Mailfilter you can define your own filters (rules) to deter- mine which e-mails should be delivered and which are considered waste. Rules are Regular Expressions, so you can make use of famil- iar options from other mail delivery programs such as e.g. procmail. . If you do not get your mail from a POP3-Server you don't need Mailfilter. </DESCRIPTION> It can be plugged into fetchmail, which I'm going to do as soon as I upgrade to my new (hopefully quiet) Shuttle SK41G. Since all my clients are Linux, I might not need Amavis after that. -- ----------------------------------------------------------------- Ron Johnson, Jr. [EMAIL PROTECTED] Jefferson, LA USA The difference between Rock&Roll and Country Music? Old Rockers still on tour are pathetic, but old Country singers are still great. ------------------------------------------------------- This sf.net email is sponsored by:ThinkGeek Welcome to geek heaven. http://thinkgeek.com/sf _______________________________________________ Spamassassin-talk mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/spamassassin-talk
