At 08:35 AM 04/21/96, you wrote:
>Hi, The way I stop this is to disable the telnetd in /etc/inetd.conf on
>the machine running sendmail. Your mailhost machine. If your local users
>are running Unix take away the execute permission on telnet and make it
>so only the root user can run telnet. Also you can do the same for rlogin
>make it so only root can run rlogin, this way you as administrator will
>be able to rlogin to your local machines but regular users will neither be
>able to run telnet to local machines or rlogin. If your local users are
>running DOS/WINDOWS or whatever they will not be able to telnet port 25
>to the mail server and this should fix your problem of fake mail.
I guess I did not provide enough info in the first posting. Sorry. Ill try
to clear it up now.
Shutting down telnetd is a good idea. This was considered. Unfortunatly,
we do not have a dedicated mailhost. Instead we have three main machines
(one VAX and two suns) that must remain open to telnet (port 23). They key
would be able to shut down telnet to 25 and allow telnet to 23. (This is
sounding like a key firewall question to me. If it is possible, please tell
The users on campus access mail in a variety of ways. Some telnet to the
suns and use unix accounts (mail or pine) to send mail. Some telnet to the
vax to send mail (mail or pine again). Some use windows/dos based pop
mailers (pop-mail, eudora, pegasus, etc) to use the pop3 daemon on the vax.
There is no pop mail support on the suns.
Not only this, but access is allowed from both lab computers and room machines.
So unfortunaly shutting down telnet is not a viable option.
Thanks for the good sugestion,
John P. Mulligan <mulligaj @
PGP PUBLIC KEY available at http://www.lafayette.edu/~mulligaj
"Perhaps you think your Email is legitimate enough that encryption is
unwarranted. If you really are a law-abiding citizen with nothing to hide,
then why don't you always send your paper mail on postcards? ... Are
you trying to hide something?" --- Pretty Good Privacy (PGP) Manual