Gene Heskett wrote:
A good idea, if the firewall box had the cojones to do it. Its a 500mhz k6-III, and already running the firewall duties fairly fast, but adding that load to it does concern me somewhat.
I don't recall you posting any details of what sort of mail volume you're running, but I have some experience running SA on small hosts for anywhere from low to high (for the hardware) mail volumes.
One system I had an account calling SA on for a time was a P133 with ~48M memory, IIRC. (This was ~SA2.2 or so, though.) That system handled maybe five active accounts, to the tune of ~20K messages per month. Along with webhosting, FTP, SSH, VNC, some bits and pieces of X, etc, etc, etc. (I think that box may still be in service.)
Somewhere along the line I moved my own domain off of that machine (due to @#^#$%^$^% Bell Canada doing something funky to its DSL connection for a month or so) and onto a dual PII/266/128M box. Between changes in my mail flow and SA versions, that system held up fine under SA2.6something, with my ~6K spams per month, plus Asian mailing lists that I still haven't figured out where I got on, plus webhosting, anonFTP for my domain, etc, etc, etc... I replaced (with a dual P3/866) it because I wanted more CPU power for something, not because it couldn't handle the day-to-day mail load. <g>
In a more formal environment, under higher load, I've been administering both a domain hosting box, and "regular" ISP customer spamfilter box for quite a few years now. The hosting box has seen a peak of ~40 domains, mostly spamfiltered, and hosts EVERYTHING on one box. Currently, it's a PII/400/192M, and the overall load is near-zero most of the time. It's been handling between 8K and 10K messages per week for at least a year and a half.
The spamfilter box has gone through a number of incarnations. It started out as a P2/450/256M, and due to the SA load was quickly upgraded to 512M. Due to customer demand, it was later replaced with the current hardware (P3/866/512M). At peak usage, it was handling over 100K messages per week, to the tune of ~1G of data volume - for more than 6 months. In December 2004, the systems that feed it had front-line RBLs added and the message volume dropped to ~40K per week, where it's pretty much stayed since then. (It's at the tail end of ~3 relays - ah, legacy setups.)
It *did* need a little tweaking and beating to keep mail moving, in the form of tuning sendmail and MIMEDefang process/load limits, and a custom program called from /etc/procmailrc to delay SA processing and mail delivery while system load was high. That box was last rebooted in April 2004. <g>
Your idling K6 should NOT have trouble with your mail flow. About the only upgrade you MIGHT want to make is add more memory (you didn't say how much is in it), but I don't think that will really be an issue.
(As for firewall services.... For quite some time, my DSL connection at home was through a P133/48M box. It was quite happy to pass full-bandwidth downloads through to my desktop while I was torturing it with hosting a local Quake2 server for my LAN. <g>)
-kgd
