I realise this has been covered before, but I'm having a problem with getting outbound mail to a destination domain. The ISP in question has an interesting policy of refusing messages sent to a single email address in excess of 30/min. Their servers also go on and offline at random intervals, due to telecoms issues. We have an application that sends messages to a single recipient on the destination domain, usually in excess of 200 a day. If a server has gone offline for a while, naturally we have a backlog of mail waiting to deliver when the server is up again, and we quickly exceed the 30/min limit. I've upgraded a server to Postfix 2.5.2 (from 2.2) and tried implementing a slow transport for this purpose: master.cf ----------- # transport for touchy domains slow unix - - n - 1 smtp
main.cf --------- slow_destination_concurrency_limit = 1 slow_destination_rate_delay = 2 transport ----------- solomon.com.sb slow: However, at the next retry interval, the entire queue is trying to empty itself concurrently: Aug 13 15:59:14 smtptest postfix/error[4456]: 4569E15E00F9: to=<[EMAIL PROTECTED]>, relay=none, delay=3283, delays=3282/0.08/0/0.01, dsn=4.4.1, status=deferred (delivery temporarily suspended: connect to mx.telekom.net.sb[202.1.161.20]:25: Connection refused) Aug 13 15:59:14 smtptest postfix/error[4468]: F40FE15E00BD: to=<[EMAIL PROTECTED]>, relay=none, delay=4906, delays=4906/0.08/0/0.01, dsn=4.4.1, status=deferred (delivery temporarily suspended: connect to mx.telekom.net.sb[202.1.161.20]:25: Connection refused) Aug 13 15:59:14 smtptest postfix/error[4476]: 6023715E009D: to=<[EMAIL PROTECTED]>, relay=none, delay=4905, delays=4905/0.08/0/0, dsn=4.4.1, status=deferred (delivery temporarily suspended: connect to mx.telekom.net.sb[202.1.161.20]:25: Connection refused) Aug 13 15:59:14 smtptest postfix/error[4460]: 4061815E00C0: to=<[EMAIL PROTECTED]>, relay=none, delay=4906, delays=4905/0.08/0/0.01, dsn=4.4.1, status=deferred (delivery temporarily suspended: connect to mx.telekom.net.sb[202.1.161.20]:25: Connection refused) [... 75 messages in the queue] I expect the messages to try filtering themselves out at a rate of one every two seconds to this destination, not all of them in the same second. Could someone please clarify what I've omitted or misunderstood here? Thanks.
