On Wed, Aug 09, 2006 at 06:50:18PM +0200, openbsd misc wrote:
> >> (I want to) use a standard smtp daemon (sendmail, postfix or
> >> whatever) and put the spooling directory in a ramdisk :-)
> > Don't bother with the ramdisk. disk is cheap and fast compared
> > to smtp.
> > Fooling around with ramdisk/passthough stuff is more trouble
> > than it is worth.
>
> The only thing I can use is a ramdisk. I want it to run on a wrap
> system. Writing to the cf card is not an option, and all I have
> are 128MB RAM. There are only two options:
>
> - forward 25 -> exchange (not a good one... I think you know why ;-))
> - checking envelope informations -> forward to exchange, stream the
> message
>
> I hope that makes it clearer (my mistake in my first mails ;-))
I agree with the other posters that this is not a good idea. Try an old
laptop (less small, but accepts a standard disk and should be cheap), a
remote NFS server (getting the mail spool to work reliably is (usually?)
possible, but pay close attention to the docs), just writing to CF
(allegedly, it isn't too expensive), any other old box, paying someone
else to take your mail, and so on and so forth. This is not to say that
ramdisks need to be completely unreliable - using a stable system such
as OpenBSD and a UPS would probably deliver acceptable reliability - the
UPS I just mentioned is probably larger than a
small-but-not-so-small-as-to-not-accept-any-disk box.
Also note that small boxes of the kind you seem to have, while they
cannot hold mail, are perfectly suited for terminating IPsec tunnels
from boxes that can, and can do service as a packet filter on top of
that without breaking a sweat on typical residential lines.
Finally, quite a few outputs can be abused to provide an interface that
can run either a disk or a network (and, hence, NFS) - slip can be used
to abuse serial lines as network cables, and the CF adapter is likely to
plug into something that groks IDE somewhere.
However, if all this fails, what you're looking for could be called a
'transparent smtp proxy'; Google gives quite a few hits, and the very
first looks similar to what you try to achieve. Given the quality of the
text, though, I wouldn't vouch for the quality of the software.
Given MS' typical costs in hardware and licenses, though, I don't really
understand why you don't have a little money for a decent gateway. Plus,
Exchange isn't *that* insecure when properly configured, firewalled, and
so on - certainly no worse than a random program you downloaded of the
internet with questionable quality and goals [1].
Joachim
[1] Come to think of it, that describes most Windows software.
Come to think of it, that describes most software - period. Oh well, at
least you get the source to this particular disaster.
