Re: Mail architecture for up 30.000 accounts
On Fri, 30 May 2003 19:34, Bart Matthaei wrote:
> > For software, I would use this:
> > SMTP: Postfix
> Postfix works fine. Sendmail or qmail would do the trick as well. Depends
> on your personal preference.
If you want to run a machine for years on end without needing an urgent
security-related upgrade then Sendmail will not do the job.
You can install Postfix or Qmail and expect that you can leave them run for a
few years without incident.
> > IMAP: Courier
> > POP3: Courier
Yes, Courier is good.
> > Authtentication and user preferences: MySQL
> You should check if both your MTA, IMAP/POP3, and delivery agent (procmail
> for instance) will support MySQL authentication.
I suggest LDAP.
> > Webmail: IMP
> Don't use IMP for a large userbase. IMP is slow and bloated. The interface
> is really slick, but it's a real CPU/MEM hog.
CPU and RAM are getting cheap now. I was recently involved in moving a large
ISP from Netscape to open source software. It had well over 1M accounts,
over 500,000 accounts that were in active use, and something over 50,000
accounts in active use for webmail.
When I finished working for them there were two IMP machines in the webmail
cluster and a third was added later. One machine could handle the load on
it's own if necessary (although at peak times one machine would be a
bottleneck). The machines had 4G of RAM (excessive - 2G would have been
plenty) and 2 * 1.8GHz P4 Xeon CPUs with Hyper-threading.
Linux 2.4.x doesn't schedule things on hyper-threaded SMP machines as well as
you may desire, so single-CPU machines are probably better value for money.
I suggest having machines with a single Athlon or Xeon CPU that's as fast as
possible for IMP servers. For 30,000 users then two machines that each have
a fast Athlon or Xeon CPU and 1G of RAM should do fine.
I'm not strictly advocating IMP here. But I found it to work fine when I had
to run it.
One problem with IMP is that you'll want the latest version which needs lots
of things that aren't in woody. I ended up making my IMP servers run
unstable for this. Also you need PHP 4.3 (or a patched PHP 4.2.3) for
supporting quotas on the number of messages as well as the size of a user's
Also don't run your webmail and your mail server on the same machine.
> > Anti-virus: F-Prot
> I'm not into Anti-Virus, so I can't help you there.
http://www.coker.com.au/selinux/ My NSA Security Enhanced Linux packages
http://www.coker.com.au/bonnie++/ Bonnie++ hard drive benchmark
http://www.coker.com.au/postal/ Postal SMTP/POP benchmark
http://www.coker.com.au/~russell/ My home page