Re: [cobalt-users] Mail relaying problem - Help Please

[Hendrik Runte <cobalt@xxxxxxxxxx>]

Hi Adam,

the problem is the SMTP protocol which is not meant to authenticate users
properly. The Idea of STMP was to send mails "blindly" no matter from whom
or to where the mail will go.

The more domains you put into the gui field 'relay for following...'
(written in /etc/mail/access) the more you open your SMTP server. At the end
you will have tons of domains.

The one solution (not the best) is to edit /etc/mail/acces by inserting
whole networks. For example, one of your customers dials in via an ISP and
gets its IP address: 194.216.33.95, eg. You may put the two first numbers in
the access table: 194.216

But this means finding out all possible IP addresses. In the end you will
get mail from ORBS telling you that they detected an open relay in your
system.

The second and better way in protecting your server against SPAM is to check
the advice on ORBS: http://www.orbs.org
There is a section especially for Sendmail 8.9 (your Raq3 will have this
one) and on how to protect it.

The beste solution seems to me to look at
http://www.cobalt.com/support/download/raq3.eng.html for the POP-before-SMTP
udpdate found here:
http://ftp.cobalt.com/pub/packages/raq3/eng/RaQ3-en-System-4.0.7-9229.pkg

This will cause POP3 authentication first before users can send mail via
your server within the following 15 minutes. If user is not authenticated by
POP3, ie. he has no account at yours or he did not check for mail first, he
will not be able to send.  Check the description (pdf) on the download site.

Good luck,

Hendrik.
--
am 13.03.2001 10:46 Uhr schrieb Adam Smith unter adam.smith@xxxxxxxxxxx:

> I am trying to relay mail through our RaQ3 server except it keeps coming up
> as mail relaying denied.  It will only relay mail if we put the domain name
> of the email address we are trying to send to in the 'Relay for following
> Hosts/Domains'.
> 
> Obviously we can't put in every domain name we are trying to send mail to,
> is there a way round this.
> 
> Thank you in advance
> 
> Adam Smith
> 
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