On Thu, 04 Oct 2001, Philip S Tellis spewed into the ether:
On Tue, 2 Oct 2001, abhijeet wrote:
1.> If the mail server doesn't check who i
am when accepting a
message for delivery......doesn't that mean that anybody could use
somebody else's mail id to send mail????
Yes. Try it and see. That's how spammers send you mail, that's how
email is forged, that's the reason why you should digitally sign your
emails with a PGP/GPG signature that only you have.
This depends on how the mail
server is configured. Normally, your mail
server is configured to relay anything from a particular range of ip
addresses, and drop everything else.
Some strict settings on the mail server, but they
legitimate users. Remember how we all reacted when vsnl blocked
non-vsnl users from sending mail.
Use SMTP AUTH or POP before SMTP.
Basically, don't allow relay from any address not
in your domain,
unless the destination address is in your domain. This could be
fixed by having your users' smtp server different from your actual
mailhost - the one with the MX entry in your DNS.
Relay from, or relay to?
You relay to everything in your domain, and for everyone in your ip
Check the IP of the source host. Don't allow
relay from any host
that doesn't have a DNS entry, and isn't from your IP pool.
Thats a bit
strict, plenty of people don't fix their DNS for dialups.
Its a useful spam block though :).
"Jesus may love you, but I think you're garbage wrapped in skin."
-- Michael O'Donohugh