Re: sendmail relaying on FreeeBSD 5.4

From: John Rushford (jrushford21_at_comcast.net)
Date: 05/18/05 

Date: Tue, 17 May 2005 19:28:43 -0600

John Rushford wrote:
> Greetings,
>
> I have a mail server running FreeBSD 5.4 and assumed that relaying was
> denied by default. I have found that on my machine that this is not the
> case, the machine will relay email. The only change that I made was to
> add smtp authentication, handbook procedure, to the m4 configuration
> file. I found that a misconfigured mail client not setup with smtp
> authentication could still send email through the machine.
>
> Can someone help me with the configuration info I need to deny relaying
> and only allow clients that authenticate to send email through the
> machine. I have looked through the handbook and cannot find this info.
>
> thanks
> John Rushford
> jjr@alisa.org

I found the problem, relaying is denied if you are using smtp. I didn't
mention that I am using stunnel on this server and that the mail client
is setup to use SSL smtps on port 465. When the client sends an email
to port 465 after it gets thru the SSL wrapper the email is then sent to
  smtp port 25 and the relay host is then identified as localhost and
the email gets through un-authenticated.

Is this a bug? How can I configure the mail server to require
authentication even when coming from localhost as I do not want people
to use may email server as relay via SSL and port 465?

thanks
John Rushford
jjr@alisa.org

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