> I suspect the real problem was that hundreds of domains were not > directed to the low-concurrency 'outlook' transport, and that > connection count 'overshoot' due to unused cached connections was > a red herring.
Please recall that I collected 383 email domains into transport.outlook.regexp. I confirmed that all traffic going to outlook.com mx servers were going through the outlook: transport. I can not speak to the 'overshoot' issue. I have a set of outlook.com associated logs where (1) the outlook: transport was limited to 4 processes, (2) our email arrival rate was 500/minute and (3) outlook.com servers complained of MaxConnections. I would be glad to share this set of logs in hopes of answering the question: Is it rate limitations or connection limitations that causes outlook to issue MaxConnections? I can not share this log here due to size and the email addresses it contains. Please let me know if there is an email address I should send these logs to. PS. I also have configured the following in main.cf: smtpd_recipient_restrictions = check_recipient_mx_access regexp:/etc/postfix/mx_access.regexp as a way to get all outlook.com traffic to flow thru the outlook: transport. More on this later. Thanks, Greg www.RayStedman.org
