On Mon, 17 Nov 2003, Eduardo Alfonso wrote: > Hi > > I've been trying to configure SpamAssasin to check for the existence of the user on > the local machine that is > trying to send the message and I couldn't find how to do this. > > Is it possible ?? > > Thanx > > I'm using sendmail MTA in a RedHat9 box
If I understand you correctly, what you want is something that will examine an incoming message and try to dynamically verify that the sender of record (mail from: <[EMAIL PROTECTED]> ) is indeed a valid user at the remote system. What you're looking for is something like this: http://www.snert.com/Software/milter-sender/index.shtml Altho it sounds like a good idea, it has potential problems. If you're a low traffic site, it wouldn't be too bad, but if you handle > 10k messages a day, it would increase your network load and could be potentially abusive of remote sites that are innocent bystanders. (spammers often use randomly generated fake hotmail/yahoo/msn addresses.) Some legitimate lists send out messages with a deliberatly invalid 'from' address (they don't want to be bothered with bounces). This kind of system would block such messages. Some systems have an incoming gateway that will accept -everything- and let an internal mail server decide if the user is valid, thus making the sender verification system useless. Some heavily loaded systems (such as hotmail) occasionally get backed up for hours at at time and not accept connections. This would slow down your incoming mail from those sites, not to mention putting addtional load on their servers. What might be a better solution would be to interlock your MTA with some kind of database & SA. When a message gets rejected by a remote site with a DSN, put that address in the database as invalid and then have SA take that into consideration when scoring more messages from that address. You can do that by hand editing your sendmail access-db to add rejects for specific bogus "from:" addresses. It might be a worthwhile project to try to automate the process. Dave -- Dave Funk University of Iowa <dbfunk (at) engineering.uiowa.edu> College of Engineering 319/335-5751 FAX: 319/384-0549 1256 Seamans Center Sys_admin/Postmaster/cell_admin Iowa City, IA 52242-1527 #include <std_disclaimer.h> Better is not better, 'standard' is better. B{ ------------------------------------------------------- This SF. Net email is sponsored by: GoToMyPC GoToMyPC is the fast, easy and secure way to access your computer from any Web browser or wireless device. Click here to Try it Free! https://www.gotomypc.com/tr/OSDN/AW/Q4_2003/t/g22lp?Target=mm/g22lp.tmpl _______________________________________________ Spamassassin-talk mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/spamassassin-talk
