Mail server with port-blocking ISP (Was: Re: Looking for classes and advice)

[Mike Schwartz]

On 2/26/07, Eric Shubes <plug at shubes.net> wrote:
>
> Craig White wrote:
> > On Mon, 2007-02-26 at 02:51 -0700, David Bendit wrote:
> >> -----BEGIN PGP SIGNED MESSAGE-----
> >> Hash: SHA1
> >>
> >> On Feb 25, 2007, at 9:44 PM, der.hans wrote:
> >>
> >>> Set up and
> >>> run your own mail server and web server. Learn how to keep your own
> >>> firewall secure and how to subnet your network for servers on one
> >>> side and
> >>> desktops on the other. If you only have two boxes, setup virtual
> >>> interfaces and pretend :). If you only have one box, setup virtual
> >>> interfaces and pretend even more.
> >> Actually, I've been wondering about this for a while, and I've never
> >> found a way to do it. Is there a way to run a mail server on a
> >> standard account (non-business) with a port-blocking ISP? I'm going
> >> through Cox, and they block all the fun ports (80, 25, and a bunch
> >> more). I've even been able to set up postfix before, but only for
> >> intra-network mail. To get mail out, I had to use a relayhost, and
> >> the only way I could find to get mail in always involved a forwarder.
> >> However, with the forwarder, most spam blocking measures
> >> (greylisting, RBLs, etc.) were rendered useless. If you guys can
> >> offer any tips, that'd be great.
> > ----
> > the answer is that you can't. Things like greylisting and RBL's are only
> > useful at the point where an SMTP server that is designated as the MX
> > for your domain. Whether you retrieve your email from that system via
> > ETRN, fetchmail or other methods, at that point, the mail has already
> > been accepted and thus greylisting or RBL blocks and even bouncing mail
> > is futile or worse.
> >
> > Craig
>
> Painfully true. FWIW though, Qwest isn't block any ports on my connection
> (knock wood).
>
> --
> -Eric 'shubes'
> ---------------------------------------------------
> PLUG-discuss mailing list - [...]
>

>> However, with the forwarder, most spam blocking measures
>> (greylisting, RBLs, etc.) were rendered useless. If you guys can
>> offer any tips, [...]

Well, my (personal) "business card" e-mail address is a
forwarding address ("schwartz at acm.org") that I have had
since 1992.
(actually, for a while acm.org even offered shell accounts
 [not Linux - it was Vax VMS], so for a while it was
 actually a 'regular' [not "forwarding"] address).
One of the good things is, that my address does
not change when I start to use a different mailbox - -
whether due to changing ISP's, or changing employers
or schools, or just changing from the Aztec Free-Net
to Yahoo (and then later to Google).
Another good thing is, that a few years ago, the acm.org
folks started using "postini.com" to do their detection
and "quarantining" of bulk (junk) mail, and of viri, etc.
(it also provides very easy white listing).
Now this specific example might not be for you, since
I think acm.org probably only allows use of their
forwarding addresses, for members
(but I had already been a member since 1974 anyway).
(hmmm, not sure if it includes former members;...)
Their dues are a little pricey, (except for students).
(but, I think they may also have a discount for
 those who are retired or who otherwise can't
 afford the "regular price").
   But - there might be some other places, that offer
forwarding service (for example I added another
forwarding address, which I could use,
["Mike Schwartz" <mike.schwartz at alumni.rice.edu>]
but I had already started using the acm.org address);
and if you can find one that provides
the level of detection you want for spam, viri, etc.,
then that is an option to consider.
-- 
Mike Schwartz
Glendale  AZ
schwartz at acm.org
Mike.L.Schwartz at gmail.com
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