I have made SMTP Authentication with this how-to page. http://www.sendmail.org/~ca/email/auth.html
It work fine. Any one spamer can't send mail via my smtp server.
Its never a good idea to run an open SMTP relay. Spammers live for those. I thought by default, the Fedora Core sendmail server did not allow relaying (I know you have to tweak it to accept mail from other than localhost by default). I remember when I commented out the:
dnl DAEMON_OPTIONS(`Port=smtp,Addr=127.0.0.1, Name=MTA')dnl
line, I had to allow all the machines on my local network to access sendmail through the /etc/mail/access file in order to send email.
But he can send mail via my smtp to my_user@xxxxxxxxxxxxx without authentication! How to forbid and it too?
If you want to accept email from the internet, in general, to your domain, you're kinda stuck. You can block specific users/domains/ips in the /etc/mail/access file, but if spammers change IP addresses and domain names all the time, so you're basically SOL....
I searched in the documentation to sendmail but have found nothing.
I basically gave up and started concentrating on removing the spam before it gets to my Inbox with RBL, SPF, SpamAssassin, and junk email filters in my MUA. Its still not perfect, but it helps a lot!
-- Kevin J. Cummings kjchome@xxxxxxx cummings@xxxxxxxxxxxxxxxxxx cummings@xxxxxxxxxxxxxxxxxxxxxxx
