Robert Horton <[EMAIL PROTECTED]> writes: > On Monday, May 17, 2004, at 13:16 US/Pacific, Chris Petersen wrote: > >>> For that matter how does one reject a message with a To: field that is >>> not even at my domain? >> >> You don't want to do this. Many listserv programs send "to" themselves >> (including this one). Also, don't forget that it's also completely >> possible to have a blank To field and a full Cc field (weird, but it >> works), or have a message to someone else, but cc'd to you. >> >> -Chris >> > > Very good point! I guess my question would point me back to setting up > good spam filtering then. And, like I said, I have never done that and > do not know where to begin. I have read the courier docs but they I do > not think I followed it very well. Any help/suggestions would be > appreciated. :)
You can do just about any filtering you want within what Courier calls a "global filter". You can do a "man courierfilter" to get info about this. In a global filter, you have access to all the headers and body text of a message, and you can use that info to implement your chosen filtering mechanisms, which can then be used to reject unwanted messages. The setup is a bit complex for global filters, and people have written tools to help simplify this. One such tool is the Perl package called Courier::Filter. Another is the Python package called courier-pythonfilter. Courier provides another filtering mechanism called "local filters". These are applied later in the message delivery process, after the "global filters" have provisionally passed the messages. You can use maildrop or other similar packages to aid in this local filtering. Do a "man localmailfilter" for info. I should warn you, however, that in addition to understanding how Courier delivers messages, you also need to have a fairly extensive knowledge of internet protocols in order to have any kind of success at filtering spam using your own, home-grown methods. You need to look at the RFC's (official internet protocol specifications) and understand what is _supposed_ to happen when email is being delivered before you can begin to understand how to block the illegal stuff. A good RFC to start with is RFC-2821. If you want to punt on all this, you can make use of software like SpamAssassin and TMDA (to name two out of many), which are pre-written packages that work with most MTA's. If used correctly, these do a fairly good job at spam protection. But I still recommend you read and understand (at least at a high level) RFC-2821 and other similar documents. -- Lloyd Zusman [EMAIL PROTECTED] God bless you. ------------------------------------------------------- This SF.Net email is sponsored by: SourceForge.net Broadband Sign-up now for SourceForge Broadband and get the fastest 6.0/768 connection for only $19.95/mo for the first 3 months! http://ads.osdn.com/?ad_id=2562&alloc_id=6184&op=click _______________________________________________ courier-users mailing list [EMAIL PROTECTED] Unsubscribe: https://lists.sourceforge.net/lists/listinfo/courier-users
