Re: Sendmail 8.11 configuration/security issue

[Wahyu Kelik <mahapatih () bunga compeng org>]

On Fri, Jan 03, 2003 at 04:53:08PM -0600, Ned Fleming wrote:
> [snip]
>
> Are you using the FEATURE(relay_local_from) in Sendmail? This feature
> allows relaying if the message claims to originate at your domain.
> Since forging this address is trivial, this is probably a bad idea.
> But I'm no Sendmail expert. My best advice would be to switch to
> Postfix, which is orders of magnitude easier to configure.

Beside change to postfix, you can point to sendmail authentication
configuration (using STARTTLS and SMTP AUTH).
I use SMTP AUTH for internal user, and /etc/mail/access.db for
external mail server (just limited to server that allows to relay).

I add this one to my sendmail.mc

define(`confAUTH_OPTIONS', `A')dnl
define(`confAUTH_MECHANISMS', `CRAM-MD5 DIGEST-MD5 LOGIN')dnl
TRUST_AUTH_MECH(`CRAM-MD5 DIGEST-MD5 LOGIN')dnl

Regards,
-kelik-