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author | John Denker <jsd@av8n.com> | 2012-06-01 18:58:45 -0700 |
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committer | John Denker <jsd@av8n.com> | 2012-06-01 18:58:45 -0700 |
commit | b732a73bc773789894466b0e5320b2f1fe42c7e9 (patch) | |
tree | 385358983f064a1f10a5080b33a3ba13010886db /BLURB4 | |
parent | 634d365a03cb0581a062cd3cf4db9ae69f1cde26 (diff) |
original, as downloaded from http://www.qmail.org/netqmail-1.06.tar.gz
Diffstat (limited to 'BLURB4')
-rw-r--r-- | BLURB4 | 44 |
1 files changed, 44 insertions, 0 deletions
@@ -0,0 +1,44 @@ +qmail's modular, lightweight design and sensible queue management make +it the fastest available message transfer agent. Here's how it stacks up +against the competition in five different speed measurements. + +* Scheduling: I sent a message to 8192 ``trash'' recipients on my home +machine. All the deliveries were done in a mere 78 seconds---a rate of +over 9 million deliveries a day! Compare this to the speed advertised +for Zmailer's scheduling: 1.1 million deliveries a day on a +SparcStation-10/50. (My home machine is a 16MB Pentium-100 under BSD/OS, +with the default qmail configuration. qmail's logs were piped through +accustamp and written to disk as usual.) + +* Local mailing lists: When qmail is delivering a message to a mailbox, +it physically writes the message to disk before it announces success--- +that way, mail doesn't get lost if the power goes out. I tried sending a +message to 1024 local mailboxes on the same disk on my home machine; all +the deliveries were done in 25.5 seconds. That's more than 3.4 million +deliveries a day! Sending 1024 copies to a _single_ mailbox was just as +fast. Compare these figures to Zmailer's advertised rate for throwing +recipients away without even delivering the message---only 0.48 million +per day on the SparcStation. + +* Mailing lists with remote recipients: qmail uses the same delivery +strategy that makes LSOFT's LSMTP so fast for outgoing mailing lists--- +you choose how many parallel SMTP connections you want to run, and qmail +runs exactly that many. Of course, performance varies depending on how +far away your recipients are. The advantage of qmail over other packages +is its smallness: for example, one Linux user is running 60 simultaneous +connections, without swapping, on a machine with just 16MB of memory! + +* Separate local messages: What LSOFT doesn't tell you about LSMTP is +how many _separate_ messages it can handle in a day. Does it get bogged +down as the queue fills up? On my home machine, I disabled qmail's +deliveries and then sent 5000 separate messages to one recipient. The +messages were all safely written to the queue disk in 23 minutes, with +no slowdown as the queue filled up. After I reenabled deliveries, all +the messages were delivered to the recipient's mailbox in under 12 +minutes. End-to-end rate: more than 200000 individual messages a day! + +* Overall performance: What really matters is how well qmail performs +with your mail load. Red Hat Software found one day that their mail hub, +a 48MB Pentium running sendmail 8.7, was running out of steam at 70000 +messages a day. They shifted the load to qmail---on a _smaller_ machine, +a 16MB 486/66---and now they're doing fine. |