Sendmail relaying problem (1/2 Noob!)

Nerd2 · 08-19-2003, 06:15 AM

Hello guys!

I need some help here. I have a IMAP / SMTP server using sendmail 8.12.8 for the SMTP. (REDHAT 8.0) The problem i'm having is that whereever I send email using my server, it relays perfectly. As far as I can see, from wherever I am, I can relay with my server with no authentication. Eek!!

What I want it to do is require a username/password to send the mail.

I've been trawling through masses of security documentation, most of which says that it shouldn't be relaying be default. I've looked in sendmail.mc and /etc/mail/access, both of which imply that relaying is denied.

Please help!

Nerd2

Looking_Lost · 08-19-2003, 12:28 PM

What do you mean by from where ever you are, on a completely different computer outside your network?

Nerd2 · 08-19-2003, 05:48 PM

Yes.

I am here, logged onto freeserve.

Sending email to:

My server, on blueyonder broadband. (10 miles away)

Forwarding the email to:

anyone (x miles away)

Looking_Lost · 08-19-2003, 06:07 PM

What are the contents of your /etc/mail/access ?

Nerd2 · 08-20-2003, 05:06 AM

It did have:

Code:

127.0.0.1
localhost
localhost.localdomain

But I got rid of them, just to be sure. It now just has:

Code:

# Check the /usr/share/doc/sendmail/README.cf file for a description
# of the format of this file. (search for access_db in that file)
# The /usr/share/doc/sendmail/README.cf is part of the sendmail-doc
# package.
#
# by default we allow relaying from localhost..

Thanks

Nerd2

N.B. For reference: My sendmail.mc:

with comments

without comments

Nerd2 · 08-20-2003, 07:14 AM

I've figured it out.

When I telneted to port 25 on my server (to see what sendmail version responded), I got a response from a completely different server. It it now clear that freeserve are redirecting all port 25 queries to their own SMTP server. That is why it appeared that my server was relaying my emails.

Thanks anyway guys.

Nerd2

unSpawn · 08-20-2003, 06:37 PM

Does that mean you put the access restrictions back in?

Nerd2 · 08-21-2003, 05:35 PM

The access restrications were always in. I thought my server was relaying without authorization, when in fact it was the freeserve server that was relaying, with authoization (from me logging on to their dial-up)

My server is now on another port, and doesn't work anyhooo!