Relays Question

We recently ran into a problem on our network with viruses. I believe
it was
a series of issues caused by our service provider. First, an Anti-
Virus
version update was botched and large number of systems were
unprotected by
AV. Second, the Firewall was configured so that anyone could send via
port
25. Third, at the same time we opened relaying internally. Can't be
sure, but
I do not believe it was related to opening up relaying internally.

The question is, with the firewall configured so that only our
Exchange
server can use port 25 outgoing (connecting to another server in a DMZ
to
send the mail on), if we set up relaying so that computers on the
inside of
the network can use the Exchange server as an open relay - do we have
anything to worry about?

The reason for the question is that we are implementing new software
that is
meant to work with any e-mail server and requires POP3 and SMTP. It
requires
that the workstations have the ability to use our mail server as a
relay as
well. My concern is that if we get hit with another virus, what will
the
outcome be? Are there any viruses setup to detect open relays on a
network
and use them? I am not an expert on this matter at all, but I have to
believe
the answer is yes there are viruses smart enough to detect and use an
unspecified open relay... Thoughts?

.

Relevant Pages

  • Re: mail problem
    ... > I found out that my server has been blacklisted by some sites. ... > case there are other leaks on the network. ... it's been blacklisted for being an open relay. ... pointing at the Black List site that has you ...
    (Fedora)
  • Re: virus
    ... If the user is on your network and they are getting viruses via email, ... your anti-virus software is not doing what it should, ... your server side AV before it even gets to the users mailbox. ...
    (microsoft.public.exchange.admin)
  • Re: Server reboots
    ... viruses could possible exist. ... Then install all patches, and after that, ... connect it to the network. ... > I have just received a new Gateway server (the first one ...
    (microsoft.public.windows.server.general)
  • Re: Fully parallel Scheme-based language w/ evaluator
    ... Windows Server 2003 and networks in simple - and irreverent - terms. ... If networking really is a big deal, ... Concepts and Terminology in Part I, and The Design and Deployment of Network ...
    (comp.lang.misc)
  • Re: Outgoing POP3 email missing/lost/not received
    ... Funny thing is that I have had this ISP for 8 years and it has always been ... It looks like when you last ran CEICW, you set the ISP's mail server to: ... Internet Connection Wizard. ... After the wizard completes, the following network connection ...
    (microsoft.public.windows.server.sbs)