I installed the patch for SuSE 8.0-Qpopper:
linuso:/var/cache/fou4s/packages/ftp.gwdg.de/i386/update/8.0/n4 # popper -v
Qpopper Modified by SuSE version 4.0.3 (non-standalone)
linuso:~ # rpm -qa | grep popper
qpopper-4.0.3-178
linuso:/var/cache/fou4s/packages/ftp.gwdg.de/i386/update/8.0/n4 # popauth
-version
popauth v4.0.3
After this it is not possible for the external users to authentificate with
smtp. The mail.log shows like this:
May 19 18:03:28 linuso postfix/smtpd[1638]: connect from
unknown[195.243.195.231]
May 19 18:03:28 linuso postfix/smtpd[1638]: 743BCCF4:
client=unknown[195.243.195.231]
May 19 18:03:28 linuso postfix/smtpd[1638]: reject: RCPT from
unknown[195.243.195.231]: 554