if it was ipchains you would do the follwoing ; #allowing localhost /sbin/ipchains -A input -j ACCEPT -p all -s localhost -d localhost -i lo /sbin/ipchains -A output -j ACCEPT -p all -s localhost -d localhost -i lo #Deny packets from internet claiming to be from localhost and log /sbin/ipchains -A input -j REJECT -p all -s localhost -i ppp+ -l Basically that should solve your problems for now that is u dont have a machine on your LAN spamming Rgds Duncan ----- Original Message ----- From: "Nilesh" <niluforalways@xxxxxxxxx> To: "Duncan" <drack@xxxxxxxxxx>; "General Red Hat Linux discussion list" <redhat-list@xxxxxxxxxx> Sent: Wednesday, July 28, 2004 2:31 PM Subject: Re: SendMail sending garbage mails > Hi Duncan, > > yeah I have configured IPtables firewall on that > machine and blocked incoming packtes for other ports > except 25 port and 110 > but not blocked loopback do u feel this problem is > because of loopback > > Regards > Nilesh > > > > --- Duncan <drack@xxxxxxxxxx> wrote: > > > > Hi friends, > > > > > > I have some problems with my sendmail server. > > > it has sending some garbage mails to outside and > > that > > > mails bouncing back to on different user that is > > not > > > existing users. > > > the error are like > > > ----- The following addresses had permanent fatal > > > errors ----- > > > vbqdfwhgvokn@xxxxxxxxxx > > > (reason: 550 5.5.1 No such user here) > > > > > > ----- Transcript of session follows ----- > > > ... while talking to data2.centrum.cz.: > > > > > > >>>>>> DATA > > > > > > <<< 550 5.5.1 No such user here > > > 550 5.1.1 vbqdfwhgvokn@xxxxxxxxxxxxx User unknown > > > <<< 503 5.5.2 Waiting for RCPT command > > > > > > Subject: > > > Returned mail: see transcript for details > > > From: > > > Mail Delivery Subsystem <MAILER-DAEMON> > > > Date: > > > Thu, 15 Jul 2004 21:14:34 +0530 > > > To: > > > vbqdfwhgvokn@xxxxxxxxxx > > > > > > The original message was received at Thu, 15 Jul > > 2004 > > > 21:14:34 +0530 > > > from root@localhost > > > > > > ----- The following addresses had permanent > > fatal > > > errors ----- > > > craig@xxxxxxx > > > (reason: 550 5.1.1 User unknown) > > > ----- Transcript of session follows ----- > > > 550 5.1.1 craig@xxxxxxxxxx User unknown > > > > > > could any one please tell me how to stop this. > > > redhat-list mailing list > > > unsubscribe > > > mailto:redhat-list-request@xxxxxxxxxx?subject=unsubscribe > > > > > https://www.redhat.com/mailman/listinfo/redhat-list > > > > Well you definately need a firewall on your loopback > > interface which does > > not allow outside packets to connect except yo ISP > > to smtp port > > etc..Basically do not allow packets from the outside > > .Else u have a machibe > > in your LAN with a virus that is spamming , u iwll > > have to monitor your > > maillog . > > Wat do others think ???? > > Rgds > > > > Duncan Rack > > > > > > -- > > redhat-list mailing list > > unsubscribe > > > mailto:redhat-list-request@xxxxxxxxxx?subject=unsubscribe > > https://www.redhat.com/mailman/listinfo/redhat-list > > > > > > > > __________________________________ > Do you Yahoo!? > New and Improved Yahoo! Mail - 100MB free storage! > http://promotions.yahoo.com/new_mail > -- redhat-list mailing list unsubscribe mailto:redhat-list-request@xxxxxxxxxx?subject=unsubscribe https://www.redhat.com/mailman/listinfo/redhat-list
