On Wed, 2014-07-30 at 14:23 +0000, Viktor Dukhovni wrote: > On Wed, Jul 30, 2014 at 10:06:34AM +0100, Andrew Beverley wrote: > > > Incidentally, I am submitting using the sendmail command, rather than > > SMTP (against the advice of the tuning README) - how much difference is > > this likely to make? > > This doubles the disk I/O cost of message delivery and serializes > submission because pickup(8) processes one message at a time. > > You'll likely get an order of magnitude higher throughput with 4--10 > parallel SMTP submission streams, but even a single SMTP submission > stream will likely out-perform local submission via sendmail(1) though > not by much, the real gain is in parallel submission.
Great, thanks for that. I'm going to start submitting via SMTP. One more similar question: is there much value in reusing the same connection to send each email? Obviously that removes the expense of creating a connection, but prevents parallel submission. Should I be trying to do both? I'm using Perl's Mail::Transport::SMTP module, which I would need to patch for multiple emails per connection, but am wondering whether it is worth doing do. Thanks, Andy
