Hello Carsten, you can prohibit sending mail of roaming user by pop-before-smtp (http://www.google.de/search?q=pop+before+smtp+%2B+sendmail&ie=UTF-8&oe=UTF- 8&hl=de&meta=) Smtp has no authentication mechanism, but pop has. after configured pop-before-smtp with sendmail only users with authenticated by pop first are allowed to send email through your mailserver. Jens -----Ursprüngliche Nachricht----- Von: Carsten Becher [mailto:cb-maillist@cbecher.de] Gesendet: Samstag, 26. April 2003 10:57 An: SuSE Security Betreff: [suse-security] sendmail, avoiding open relay Hoi ! I´ve a mailserver running at home (for 2 clients - nothing serious), SuSE 7.2. I´ve already restrictet access by using the /etc/mail/access to 192.168 . That´s enough or should i do something more? Background is, i got me this message by my system : ----- The following addresses had permanent fatal errors ----- <xxxxxx@xx.xx> (reason: 550 relaying to <johan@mi.cl> prohibited by administrator) ----- Transcript of session follows ----- ... while talking to smtp.kundenserver.de:
RCPT To:<xxxxx@xx.xx>
<<< 550 relaying to <xxxxx@xx.xx> prohibited by administrator 550 5.1.1 <xxxxx@xx.xx>... User unknown Look´s tight to me, or did i miss something important? cu Carsten -- Check the headers for your unsubscription address For additional commands, e-mail: suse-security-help@suse.com Security-related bug reports go to security@suse.de, not here