> In that case, you should post summary statistics from the > > delays=a/b/c/d
I don't have delays= in my logs, only delay=. I think this is because the setup I'm administering now is running postfix-2.2 (yes, I want to upgrade them, but this won't happen for at least a month). However, independently I came to the same conclusion that concurrency per-site is the limiting factor. By setting up a separate transport for yahoo messages only, we were able to increase our delivery rate from a couple of hundred messages per minute, to a few thousand / min. Yahoo told us that we were not anywhere close to sending them messages too quickly, and we should be able to send more quickly, but it's just a slower process to deliver to yahoo than to the other large ISPs, it seems, so sending more messages at a time is apparently the solution. Settings for this yahoo-specific transport: yahoo_destination_concurrency_limit = 500 yahoo_connect_timeout = 5s yahoo_data_done_timeout = 120s yahoo_data_init_timeout = 60s yahoo_helo_timeout = 120s yahoo_mail_timeout = 120s yahoo_quit_timeout = 120s yahoo_rcpt_timeout = 120s yahoo_rset_timeout = 120s I had previously tried testing by changing the concurrency limit from 20 to 40 but that had a small effect, if any. A large change has a dramatic effect. -- Cos
