> All it needs to do at the moment is some very lightweight checks on the
> source and destination addresses, the best I've come up with is the
> smtpd/smtpfwdd packages in the OpenBSD ports tree.
This stuff may require some hacking. Last time I checked, smtpd did some
awful stuff to email addresses.
> They seem a bit heavyweight for my needs and I was wondering if any simpler
> programs that exist that just listen for connections, check that the HELO,
> FROM and RCPT headers and if they are valid pass the data through to the
> main server.
>
> Does anything like this exist?
>
> Any good reading material, RTFM's/A HREF's?
http://www.faqs.org/rfcs/rfc2505.html
> I am thinking I will probably have to write this my self as its quite a
> specialist program, but it should be fun little hack.
>
> Anybody else interested/pointers?
No point to re-invent the wheel. I'd just go ahead and install postfix.
It is very easy to set up, especially on a firewall, is a drop-in replacement
for sendmail, and has very fine-grained access controls (HELO, client
names/ips, envelope sender/rcpt, rbl). It also performs very well and is
secure by design.
http://www.postfix.org/
|