I have run test loads on QMAIL inbound delivery (messages were identical
1000 bytes plus 300+ bytes of header) where we exceeding 1200 emails per
minute (20 per second) on a single 400Mhz Intel uniprocessor Unix system
(I did not increase the lspawn limit from its default). To drive the
test we have a 350 mhz Linuz system doing (multiple) SMTP delivery to
it. Connections were all at 100mbit. Since the delivery system was also
qmail based, the 340mhz system sending mail was able to deliver at that
rate. I was not concerned about how fast it could deliver emails, only
that it could at least handle 20/second.
Your case could present other issues:
- How large are your emails (don't forget that a single non-attached
message to single user has 330 or so bytes of envelope et al overhead)?
Is the email creation done on a separate machine?
Do you smtp from that machine to the final MTA?
What is the size of your network pipe? (Divide the bit rate by 10 to get
a realistic byte rate).
Please note that the above was NOT a limitation, when I discovered that
a single slower machine could drive the faster delivery at the desired
receipt rate, I stoped testing further.
Cris Daniluk wrote:
>
> I know this question has been asked before, in sometimes quite violent
> threads, but I'll ask again anyway. We are looking to send high volume
> bulk emails to customers. The emails will be personalized to each user.
> Basically we're sending them out specific investment information which
> they ask for. That means every email is different, which limits out
> options. There are close to a million email addresses we have to send to
> each day and we'd like to be sending at a rate of 30+ emails per second
> so that we can finish in a reasonable amount of time. Currently, based
> on poor decisions in the past, NT is being used with Microsoft
> SMTP Server. The mailer writes directly to the SMTP pickup directory
> which will grab the file, try and send it, and queue it if it failts.
> Message delivery is not exceeding 5 emails per second. Because of this
> we've been considering other options. Currently the machines are 4 proc
> xeons with 512mb ram and a single scsi drive. Obviously this machine is
> not very appropriate for the task its being given... poor drive access,
> too much ram, etc. However, 4 have already been purchased for this... My
> question then is, in your honest, semi-unbiased opinions, do you think
> we would see *significant* results by switching to a qmail
> environment? Also, should this be so, which operating system should we
> be running qmail under? Which is the most "qmail friendly" in an intel
> environment? Linux or FreeBSD are the preferred solutions, but again, we
> are looking for the best overall performance results.
>
> On another note, to eliminate any possible confusion:
> - bandwidth is not an issue--the line is very under-utilized
> - we believe a key bottleneck is the limit on the maximum number of
> sockets that NT places. A connection to a sql server has to be made to
> generate each message, doubling the overhead
> - the server is also very under-utilized... ram usage never exceeds
> 160mb or so (surprise) and processor usage never exceeds 20% per
> processor or so (another shocker...).
>
> Please don't take the time to remark on whether the server was a bad or
> worse choice. Anyone who has ever worked for a large company should
> understand that you get what you're given--the people who buy the
> hardware rarely have any ties to the people who have to use it.
>
> I appreciate your input...
>
> Cris Daniluk
--
Daemeon Reiydelle
Systems Engineer, Anthropomorphics Inc.
[EMAIL PROTECTED]
