Author: michael Date: To: exim-users Subject: Re: [Exim] Exim vs sendmail vs PostFix vs Qmail
> > I have a few hundred thousand mailboxes per machine, using maildir. >
> When Brad gave his talk at the UKUUG Enterprise Management conference
> in February, I noticed that the figures for "typical ISP mail usage"
> were up to an order of magnitude lower than we have here. In other
> words, he allowed a tenth of the disk space for the average user and
> was seeing about a tenth of the connections that we see (mostly because
> he was concentrating on POP, not IMAP). If one can handle one million
> users each with 10MB disk usage (20MB or 50MB quota: i.e. 10TB of disk)
> and with 100000 concurrent IMAP connections with IMAP logins at the rate
> of 1000 per second (multiplying up from our figures here) on a single
> BSD box then I'll be both surprised and impressed.
Ok, I suppose I should have qualified that a little.
My system contains various domains with different quota, but most of
them are private dial-up customers with a quota of 6 MB per mailbox and
I have a couple hundred thousand of them per mailbox server. I offer
both IMAP and POP. At that amount of mailboxes, you can overbook your
mail stores safely, so you don't need quota*mailboxes MB storage.
I can't say something concerning rate of numer of POP3 connections,
because I only measure parallel connections, which is all that interests
me.