44 lines
2.6 KiB
Text
44 lines
2.6 KiB
Text
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.
|