Re: [courier-users] Tuning outgoing mail
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Re: [courier-users] Tuning outgoing mail
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From: Alessandro V. <ve...@ta...> - 2020-03-12 09:20:58
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On Tue 05/Nov/2019 23:41:58 +0100 Sam Varshavchik wrote: > Alessandro Vesely writes: >> On Tue 05/Nov/2019 14:26:00 +0100 Sam Varshavchik wrote: >> >>> Well, you have public.com and example.com. This limit applies to them >>> individually. Now, if both domains end up having the same MX in DNS, all 4+4 >>> (or 2+2) of public.com's and example.com's connections will get created >>> concurrently. >> >> >> Right. However, that wasn't the case. I still have the batch of messages, so >> I extracted a file of (IPv4, domain) pairs, stable sorted it by IPv4, and no, >> cox.net didn't share an IPv4 with a neighboring domain. >> >> I think a couple of connections could have been considered closed by my server >> while their server considered them to be still open, possibly because of >> intervening firewalls or routers dropping the relevant tcp reset. A fourth >> connection at that time could have been the sixth for them. Hmm... Still more >> plausible than a relativistic explanation, no? > > I wonder at what point, and how they defer mail. Do they just drop the incoming > connection, or return a 4xx error. > > Courier keeps a connection idle for a short period of time after it sends a > message, in case another message to the same domain needs to get sent. But at > some point it'll close the connection and the process terminates. Or it > terminates to be replaced by a connection to a different domain. > > In all cases Courier will attempt to do a polite SMTP shutdown, by sending a > QUIT, waiting for a response, and, if needed, doing a proper TLS teardown. The > TLS teardown, at least, will probably actually occur in couriertls after the > SMTP process terminates. > > Furthermore, I don't recall the sequence of events, and at which point an SMTP > sender slot is available for a new SMTP sender. > > But at least due to the TLS teardown handshake, if an idle open connection > times out and is in the process of getting closed, I can see how if a message > to the same domain happens to come in, a new connection gets created before the > previous one is fully gone for good. > > So, if you have something on the other side rate-limiting new connections right > up front, I can see this happening. But by the time SMTP's back and forth gets > down to business, any old connection is likely to be gone. > > But even in the case of the former, I don't think that anything needs to be > done here. Occasional deferrals are not the end of the world. It happens all > the time. Another attempt will be made soon enough. > > What would be obnoxious would be deferring mail with a 4xx, and automatically > 4xx-ing any other mail sent over the same connection, next, even if the number > of connections is now below the triggering point. That seems to be exactly what they do. Eventually I set MAXHOST=1, to avoid ending up with non-deliveries. Nevertheless, cox.net seems to greylist every 2nd message. Here is how their server behaves: grep from=<ab...@ta...>,addr=<ab...@co...>: /var/log/mail.log Mar 12 05:06:29 22 north courieresmtp: id=00000000005DC09F.000000005E69B541.00007CA2,from=<ab...@ta...>,addr=<ab...@co...>: 250 2.0.0 CF73jg8Mm91DmCF76jtGgm mail accepted for delivery Mar 12 05:08:44 22 north courieresmtp: id=00000000005DC07E.000000005E69B5C8.000004FA,from=<ab...@ta...>,addr=<ab...@co...>: 250 2.0.0 CF9EjQusI1lJtCF9HjvvU0 mail accepted for delivery Mar 12 05:08:46 22 north courieresmtp: id=00000000005DC09F.000000005E69B5CA.00000518,from=<ab...@ta...>,addr=<ab...@co...>: 452 4.1.0 <ab...@ta...> server temporarily unavailable. Refer to Error Codes section at https://www.cox.com/residential/suppor... Mar 12 05:08:49 22 north courieresmtp: id=00000000005DC0A7.000000005E69B5CB.00000539,from=<ab...@ta...>,addr=<ab...@co...>: 250 2.0.0 CF9KjFGKkooUgCF9MjNNMu mail accepted for delivery Mar 12 05:08:50 22 north courieresmtp: id=00000000005DC0B1.000000005E69B5CD.00000557,from=<ab...@ta...>,addr=<ab...@co...>: 452 4.1.0 <ab...@ta...> server temporarily unavailable. Refer to Error Codes section at https://www.cox.com/residential/suppor... Mar 12 05:08:53 22 north courieresmtp: id=00000000005DC0B9.000000005E69B5CF.0000057E,from=<ab...@ta...>,addr=<ab...@co...>: 250 2.0.0 CF9OjS8ZSus6zCF9Qj9WFm mail accepted for delivery Mar 12 05:08:54 22 north courieresmtp: id=00000000005DC0A7.000000005E69B5D1.0000059D,from=<ab...@ta...>,addr=<ab...@co...>: 452 4.1.0 <ab...@ta...> server temporarily unavailable. Refer to Error Codes section at https://www.cox.com/residential/suppor... Mar 12 05:08:57 22 north courieresmtp: id=00000000005DC0C3.000000005E69B5D3.000005BB,from=<ab...@ta...>,addr=<ab...@co...>: 250 2.0.0 CF9TjQuzX1lJtCF9UjvvXe mail accepted for delivery Mar 12 05:08:59 22 north courieresmtp: id=00000000005DC0CB.000000005E69B5D4.000005E3,from=<ab...@ta...>,addr=<ab...@co...>: 452 4.1.0 <ab...@ta...> server temporarily unavailable. Refer to Error Codes section at https://www.cox.com/residential/suppor... Mar 12 05:09:02 22 north courieresmtp: id=00000000005DC0D3.000000005E69B5D6.00000603,from=<ab...@ta...>,addr=<ab...@co...>: 250 2.0.0 CF9XjYchPBAU5CF9ZjjUwP mail accepted for delivery Mar 12 05:09:04 22 north courieresmtp: id=00000000005DC0D9.000000005E69B5D7.00000623,from=<ab...@ta...>,addr=<ab...@co...>: 452 4.1.0 <ab...@ta...> server temporarily unavailable. Refer to Error Codes section at https://www.cox.com/residential/suppor... Mar 12 05:09:07 22 north courieresmtp: id=00000000005DC0DD.000000005E69B5D9.00000645,from=<ab...@ta...>,addr=<ab...@co...>: 250 2.0.0 CF9cj84baOFPgCF9ej7zsp mail accepted for delivery Mar 12 05:09:09 22 north courieresmtp: id=00000000005DC0E1.000000005E69B5DA.00000665,from=<ab...@ta...>,addr=<ab...@co...>: 452 4.1.0 <ab...@ta...> server temporarily unavailable. Refer to Error Codes section at https://www.cox.com/residential/suppor... Mar 12 05:09:12 22 north courieresmtp: id=00000000005DC0E6.000000005E69B5DC.00000683,from=<ab...@ta...>,addr=<ab...@co...>: 250 2.0.0 CF9hj1OQsRBHKCF9jjCoDZ mail accepted for delivery Mar 12 05:09:14 22 north courieresmtp: id=00000000005DC0EC.000000005E69B5DD.000006D5,from=<ab...@ta...>,addr=<ab...@co...>: 452 4.1.0 <ab...@ta...> server temporarily unavailable. Refer to Error Codes section at https://www.cox.com/residential/suppor... Mar 12 05:09:16 22 north courieresmtp: id=00000000005DC0F1.000000005E69B5DF.000006F2,from=<ab...@ta...>,addr=<ab...@co...>: 250 2.0.0 CF9mjFGcZooUgCF9njNNXL mail accepted for delivery Mar 12 05:09:17 22 north courieresmtp: id=00000000005DC0F8.000000005E69B5E1.0000070F,from=<ab...@ta...>,addr=<ab...@co...>: 452 4.1.0 <ab...@ta...> server temporarily unavailable. Refer to Error Codes section at https://www.cox.com/residential/suppor... Mar 12 05:09:20 22 north courieresmtp: id=00000000005DC0FD.000000005E69B5E2.0000072F,from=<ab...@ta...>,addr=<ab...@co...>: 250 2.0.0 CF9qjQvHk1lJtCF9rjvvft mail accepted for delivery Mar 12 05:09:21 22 north courieresmtp: id=00000000005DC100.000000005E69B5E4.0000074C,from=<ab...@ta...>,addr=<ab...@co...>: 452 4.1.0 <ab...@ta...> server temporarily unavailable. Refer to Error Codes section at https://www.cox.com/residential/suppor... Mar 12 05:09:25 22 north courieresmtp: id=00000000005DC103.000000005E69B5E5.00000769,from=<ab...@ta...>,addr=<ab...@co...>: 250 2.0.0 CF9ujGYW3LxHeCF9wjVGbW mail accepted for delivery Mar 12 05:09:26 22 north courieresmtp: id=00000000005DC106.000000005E69B5E7.00000789,from=<ab...@ta...>,addr=<ab...@co...>: 452 4.1.0 <ab...@ta...> server temporarily unavailable. Refer to Error Codes section at https://www.cox.com/residential/suppor... Mar 12 05:09:29 22 north courieresmtp: id=00000000005DC0E6.000000005E69B5E8.000007A5,from=<ab...@ta...>,addr=<ab...@co...>: 250 2.0.0 CF9yjQFp74syNCFA1jYng0 mail accepted for delivery Mar 12 05:09:30 22 north courieresmtp: id=00000000005DC10B.000000005E69B5EA.000007D6,from=<ab...@ta...>,addr=<ab...@co...>: 452 4.1.0 <ab...@ta...> server temporarily unavailable. Refer to Error Codes section at https://www.cox.com/residential/suppor... Mar 12 05:09:33 22 north courieresmtp: id=00000000005DC07E.000000005E69B5EC.000007F6,from=<ab...@ta...>,addr=<ab...@co...>: 250 2.0.0 CFA3j851OOFPgCFA4j802H mail accepted for delivery Mar 12 05:09:35 22 north courieresmtp: id=00000000005DC101.000000005E69B5ED.00000813,from=<ab...@ta...>,addr=<ab...@co...>: 452 4.1.0 <ab...@ta...> server temporarily unavailable. Refer to Error Codes section at https://www.cox.com/residential/suppor... Mar 12 05:09:38 22 north courieresmtp: id=00000000005DC09C.000000005E69B5EF.00000832,from=<ab...@ta...>,addr=<ab...@co...>: 250 2.0.0 CFA7jSZIaglsZCFA9jlHVV mail accepted for delivery Mar 12 05:13:49 22 north courieresmtp: id=00000000005DC09F.000000005E69B5CA.00000518,from=<ab...@ta...>,addr=<ab...@co...>: 250 2.0.0 CFEAjGbVvLxHeCFECjVI2W mail accepted for delivery Mar 12 05:13:51 22 north courieresmtp: id=00000000005DC0B1.000000005E69B5CD.00000557,from=<ab...@ta...>,addr=<ab...@co...>: 452 4.1.0 <ab...@ta...> server temporarily unavailable. Refer to Error Codes section at https://www.cox.com/residential/suppor... Mar 12 05:13:58 22 north courieresmtp: id=00000000005DC0A7.000000005E69B5D1.0000059D,from=<ab...@ta...>,addr=<ab...@co...>: 250 2.0.0 CFEJjNM6BarJHCFELjoLFD mail accepted for delivery Mar 12 05:14:00 22 north courieresmtp: id=00000000005DC0CB.000000005E69B5D4.000005E3,from=<ab...@ta...>,addr=<ab...@co...>: 452 4.1.0 <ab...@ta...> server temporarily unavailable. Refer to Error Codes section at https://www.cox.com/residential/suppor... Mar 12 05:14:07 22 north courieresmtp: id=00000000005DC0D9.000000005E69B5D7.00000623,from=<ab...@ta...>,addr=<ab...@co...>: 250 2.0.0 CFESjGbjCLxHeCFEUjVI7u mail accepted for delivery Mar 12 05:14:11 22 north courieresmtp: id=00000000005DC0E1.000000005E69B5DA.00000665,from=<ab...@ta...>,addr=<ab...@co...>: 452 4.1.0 <ab...@ta...> server temporarily unavailable. Refer to Error Codes section at https://www.cox.com/residential/suppor... Mar 12 05:14:17 22 north courieresmtp: id=00000000005DC0EC.000000005E69B5DD.000006D5,from=<ab...@ta...>,addr=<ab...@co...>: 250 2.0.0 CFEcjQyV91lJtCFEejvx7y mail accepted for delivery Mar 12 05:14:18 22 north courieresmtp: id=00000000005DC0F8.000000005E69B5E1.0000070F,from=<ab...@ta...>,addr=<ab...@co...>: 452 4.1.0 <ab...@ta...> server temporarily unavailable. Refer to Error Codes section at https://www.cox.com/residential/suppor... Mar 12 05:14:24 22 north courieresmtp: id=00000000005DC100.000000005E69B5E4.0000074C,from=<ab...@ta...>,addr=<ab...@co...>: 250 2.0.0 CFEjj1S7yRBHKCFEljCprs mail accepted for delivery Mar 12 05:14:27 22 north courieresmtp: id=00000000005DC106.000000005E69B5E7.00000789,from=<ab...@ta...>,addr=<ab...@co...>: 452 4.1.0 <ab...@ta...> server temporarily unavailable. Refer to Error Codes section at https://www.cox.com/residential/suppor... Mar 12 05:14:33 22 north courieresmtp: id=00000000005DC10B.000000005E69B5EA.000007D6,from=<ab...@ta...>,addr=<ab...@co...>: 250 2.0.0 CFEtjQJj84syNCFEvjYpWP mail accepted for delivery Mar 12 05:14:36 22 north courieresmtp: id=00000000005DC101.000000005E69B5ED.00000813,from=<ab...@ta...>,addr=<ab...@co...>: 452 4.1.0 <ab...@ta...> server temporarily unavailable. Refer to Error Codes section at https://www.cox.com/residential/suppor... Mar 12 05:17:37 22 north courieresmtp: id=00000000005DC0A7.000000005E69B7DE.00002AE4,from=<ab...@ta...>,addr=<ab...@co...>: 250 2.0.0 CFHqj8BjAOFPgCFHsj82wr mail accepted for delivery Mar 12 05:17:43 22 north courieresmtp: id=00000000005DC138.000000005E69B7E6.00002C13,from=<ab...@ta...>,addr=<ab...@co...>: 452 4.1.0 <ab...@ta...> server temporarily unavailable. Refer to Error Codes section at https://www.cox.com/residential/suppor... Mar 12 05:17:50 22 north courieresmtp: id=00000000005DC109.000000005E69B7EC.00002CCE,from=<ab...@ta...>,addr=<ab...@co...>: 250 2.0.0 CFI4jSF7Eus6zCFI6j9ZJf mail accepted for delivery Mar 12 05:17:52 22 north courieresmtp: id=00000000005DC10B.000000005E69B7ED.00002CF2,from=<ab...@ta...>,addr=<ab...@co...>: 452 4.1.0 <ab...@ta...> server temporarily unavailable. Refer to Error Codes section at https://www.cox.com/residential/suppor... Mar 12 05:17:55 22 north courieresmtp: id=00000000005DC123.000000005E69B7EF.00002D3A,from=<ab...@ta...>,addr=<ab...@co...>: 250 2.0.0 CFI8jRqsRrB1NCFIAjSMXV mail accepted for delivery Mar 12 05:17:56 22 north courieresmtp: id=00000000005DC144.000000005E69B7F1.00002D93,from=<ab...@ta...>,addr=<ab...@co...>: 452 4.1.0 <ab...@ta...> server temporarily unavailable. Refer to Error Codes section at https://www.cox.com/residential/suppor... Mar 12 05:17:59 22 north courieresmtp: id=00000000005DC14A.000000005E69B7F2.00002DDF,from=<ab...@ta...>,addr=<ab...@co...>: 250 2.0.0 CFICj1UsoRBHKCFIEjCr3C mail accepted for delivery Mar 12 05:18:00 22 north courieresmtp: id=00000000005DC0A6.000000005E69B7F3.00002E1A,from=<ab...@ta...>,addr=<ab...@co...>: 452 4.1.0 <ab...@ta...> server temporarily unavailable. Refer to Error Codes section at https://www.cox.com/residential/suppor... Mar 12 05:18:03 22 north courieresmtp: id=00000000005DC11D.000000005E69B7F5.00002E54,from=<ab...@ta...>,addr=<ab...@co...>: 250 2.0.0 CFIGjSf60glsZCFIIjlKN6 mail accepted for delivery Mar 12 05:18:04 22 north courieresmtp: id=00000000005DC141.000000005E69B7F7.00002E9B,from=<ab...@ta...>,addr=<ab...@co...>: 452 4.1.0 <ab...@ta...> server temporarily unavailable. Refer to Error Codes section at https://www.cox.com/residential/suppor... Mar 12 05:18:06 22 north courieresmtp: id=00000000005DC125.000000005E69B7F8.00002EC2,from=<ab...@ta...>,addr=<ab...@co...>: 250 2.0.0 CFIKjQMPF4syNCFILjYqmN mail accepted for delivery Mar 12 05:18:07 22 north courieresmtp: id=00000000005DC124.000000005E69B7FA.00002EE1,from=<ab...@ta...>,addr=<ab...@co...>: 452 4.1.0 <ab...@ta...> server temporarily unavailable. Refer to Error Codes section at https://www.cox.com/residential/suppor... Mar 12 05:18:10 22 north courieresmtp: id=00000000005DC07E.000000005E69B7FC.00002EFE,from=<ab...@ta...>,addr=<ab...@co...>: 250 2.0.0 CFINjYjCVBAU5CFIPjjXsU mail accepted for delivery Mar 12 05:18:11 22 north courieresmtp: id=00000000005DC0BE.000000005E69B7FE.00002F1E,from=<ab...@ta...>,addr=<ab...@co...>: 452 4.1.0 <ab...@ta...> server temporarily unavailable. Refer to Error Codes section at https://www.cox.com/residential/suppor... Mar 12 05:18:14 22 north courieresmtp: id=00000000005DC0D6.000000005E69B7FF.00002F3B,from=<ab...@ta...>,addr=<ab...@co...>: 250 2.0.0 CFISj8C7yOFPgCFITj838v mail accepted for delivery Mar 12 05:18:16 22 north courieresmtp: id=00000000005DC0D3.000000005E69B801.00002F5A,from=<ab...@ta...>,addr=<ab...@co...>: 452 4.1.0 <ab...@ta...> server temporarily unavailable. Refer to Error Codes section at https://www.cox.com/residential/suppor... Mar 12 05:18:18 22 north courieresmtp: id=00000000005DC07E.000000005E69B802.00002F8A,from=<ab...@ta...>,addr=<ab...@co...>: 250 2.0.0 CFIWjFMVRooUgCFIXjNQPl mail accepted for delivery Mar 12 05:18:19 22 north courieresmtp: id=00000000005DC129.000000005E69B804.00002FA7,from=<ab...@ta...>,addr=<ab...@co...>: 452 4.1.0 <ab...@ta...> server temporarily unavailable. Refer to Error Codes section at https://www.cox.com/residential/suppor... Mar 12 05:18:22 22 north courieresmtp: id=00000000005DC09C.000000005E69B806.00002FC8,from=<ab...@ta...>,addr=<ab...@co...>: 250 2.0.0 CFIZjR15c1lJtCFIbjvyI7 mail accepted for delivery Mar 12 05:18:52 22 north courieresmtp: id=00000000005DC0B1.000000005E69B5CD.00000557,from=<ab...@ta...>,addr=<ab...@co...>: 452 4.1.0 <ab...@ta...> server temporarily unavailable. Refer to Error Codes section at https://www.cox.com/residential/suppor... Mar 12 05:19:55 22 north courieresmtp: id=00000000005DC0B1.000000005E69B5CD.00000557,from=<ab...@ta...>,addr=<ab...@co...>: 250 2.0.0 CFK4jYk8mBAU5CFK6jjYNk mail accepted for delivery Mar 12 05:19:56 22 north courieresmtp: id=00000000005DC0CB.000000005E69B5D4.000005E3,from=<ab...@ta...>,addr=<ab...@co...>: 452 4.1.0 <ab...@ta...> server temporarily unavailable. Refer to Error Codes section at https://www.cox.com/residential/suppor... Mar 12 05:19:58 22 north courieresmtp: id=00000000005DC0E1.000000005E69B5DA.00000665,from=<ab...@ta...>,addr=<ab...@co...>: 250 2.0.0 CFK8jFNecooUgCFKAjNQyG mail accepted for delivery Mar 12 05:20:00 22 north courieresmtp: id=00000000005DC0F8.000000005E69B5E1.0000070F,from=<ab...@ta...>,addr=<ab...@co...>: 452 4.1.0 <ab...@ta...> server temporarily unavailable. Refer to Error Codes section at https://www.cox.com/residential/suppor... Mar 12 05:20:03 22 north courieresmtp: id=00000000005DC106.000000005E69B5E7.00000789,from=<ab...@ta...>,addr=<ab...@co...>: 250 2.0.0 CFKCjGgDbLxHeCFKEjVK99 mail accepted for delivery Mar 12 05:20:04 22 north courieresmtp: id=00000000005DC101.000000005E69B5ED.00000813,from=<ab...@ta...>,addr=<ab...@co...>: 452 4.1.0 <ab...@ta...> server temporarily unavailable. Refer to Error Codes section at https://www.cox.com/residential/suppor... Mar 12 05:20:07 22 north courieresmtp: id=00000000005DC0E7.000000005E69B859.000037E7,from=<ab...@ta...>,addr=<ab...@co...>: 250 2.0.0 CFKHjYkKwBAU5CFKIjjYST mail accepted for delivery Mar 12 05:20:09 22 north courieresmtp: id=00000000005DC0F0.000000005E69B85A.00003802,from=<ab...@ta...>,addr=<ab...@co...>: 452 4.1.0 <ab...@ta...> server temporarily unavailable. Refer to Error Codes section at https://www.cox.com/residential/suppor... Mar 12 05:20:11 22 north courieresmtp: id=00000000005DC14E.000000005E69B85C.0000381E,from=<ab...@ta...>,addr=<ab...@co...>: 250 2.0.0 CFKLjRsLErB1NCFKMjSNHm mail accepted for delivery Mar 12 05:20:12 22 north courieresmtp: id=00000000005DC153.000000005E69B85E.00003842,from=<ab...@ta...>,addr=<ab...@co...>: 452 4.1.0 <ab...@ta...> server temporarily unavailable. Refer to Error Codes section at https://www.cox.com/residential/suppor... Mar 12 05:20:15 22 north courieresmtp: id=00000000005DC159.000000005E69B85F.0000385F,from=<ab...@ta...>,addr=<ab...@co...>: 250 2.0.0 CFKPjGgRoLxHeCFKQjVKFM mail accepted for delivery Mar 12 05:20:17 22 north courieresmtp: id=00000000005DC15C.000000005E69B861.0000387B,from=<ab...@ta...>,addr=<ab...@co...>: 452 4.1.0 <ab...@ta...> server temporarily unavailable. Refer to Error Codes section at https://www.cox.com/residential/suppor... Mar 12 05:20:20 22 north courieresmtp: id=00000000005DC0C3.000000005E69B862.00003897,from=<ab...@ta...>,addr=<ab...@co...>: 250 2.0.0 CFKTj8DFUOFPgCFKVj83gD mail accepted for delivery Mar 12 05:22:45 22 north courieresmtp: id=00000000005DC138.000000005E69B7E6.00002C13,from=<ab...@ta...>,addr=<ab...@co...>: 250 2.0.0 CFMpjNSG7arJHCFMrjoODN mail accepted for delivery Mar 12 05:22:54 22 north courieresmtp: id=00000000005DC10B.000000005E69B7ED.00002CF2,from=<ab...@ta...>,addr=<ab...@co...>: 452 4.1.0 <ab...@ta...> server temporarily unavailable. Refer to Error Codes section at https://www.cox.com/residential/suppor... Mar 12 05:22:59 22 north courieresmtp: id=00000000005DC144.000000005E69B7F1.00002D93,from=<ab...@ta...>,addr=<ab...@co...>: 250 2.0.0 CFN2j8F6kOFPgCFN4j84UO mail accepted for delivery Mar 12 05:23:01 22 north courieresmtp: id=00000000005DC0A6.000000005E69B7F3.00002E1A,from=<ab...@ta...>,addr=<ab...@co...>: 452 4.1.0 <ab...@ta...> server temporarily unavailable. Refer to Error Codes section at https://www.cox.com/residential/suppor... Mar 12 05:23:07 22 north courieresmtp: id=00000000005DC141.000000005E69B7F7.00002E9B,from=<ab...@ta...>,addr=<ab...@co...>: 250 2.0.0 CFNBj1YNERBHKCFNCjCsZf mail accepted for delivery Mar 12 05:23:09 22 north courieresmtp: id=00000000005DC124.000000005E69B7FA.00002EE1,from=<ab...@ta...>,addr=<ab...@co...>: 452 4.1.0 <ab...@ta...> server temporarily unavailable. Refer to Error Codes section at https://www.cox.com/residential/suppor... Mar 12 05:23:13 22 north courieresmtp: id=00000000005DC0BE.000000005E69B7FE.00002F1E,from=<ab...@ta...>,addr=<ab...@co...>: 250 2.0.0 CFNHjSiZ2glsZCFNIjlLya mail accepted for delivery Mar 12 05:23:17 22 north courieresmtp: id=00000000005DC0D3.000000005E69B801.00002F5A,from=<ab...@ta...>,addr=<ab...@co...>: 452 4.1.0 <ab...@ta...> server temporarily unavailable. Refer to Error Codes section at https://www.cox.com/residential/suppor... Mar 12 05:23:22 22 north courieresmtp: id=00000000005DC129.000000005E69B804.00002FA7,from=<ab...@ta...>,addr=<ab...@co...>: 250 2.0.0 CFNQjR4Qm1lJtCFNRjvzjE mail accepted for delivery Mar 12 05:25:12 22 north courieresmtp: id=00000000005DC0F0.000000005E69B85A.00003802,from=<ab...@ta...>,addr=<ab...@co...>: 250 2.0.0 CFPCjQRKK4syNCFPDjYt61 mail accepted for delivery Mar 12 05:25:13 22 north courieresmtp: id=00000000005DC153.000000005E69B85E.00003842,from=<ab...@ta...>,addr=<ab...@co...>: 452 4.1.0 <ab...@ta...> server temporarily unavailable. Refer to Error Codes section at https://www.cox.com/residential/suppor... Mar 12 05:25:20 22 north courieresmtp: id=00000000005DC15C.000000005E69B861.0000387B,from=<ab...@ta...>,addr=<ab...@co...>: 250 2.0.0 CFPJjgLVw91DmCFPLjtMcQ mail accepted for delivery Mar 12 05:27:56 22 north courieresmtp: id=00000000005DC10B.000000005E69B7ED.00002CF2,from=<ab...@ta...>,addr=<ab...@co...>: 250 2.0.0 CFRqjFSmmooUgCFRsjNTGz mail accepted for delivery Mar 12 05:28:02 22 north courieresmtp: id=00000000005DC0A6.000000005E69B7F3.00002E1A,from=<ab...@ta...>,addr=<ab...@co...>: 452 4.1.0 <ab...@ta...> server temporarily unavailable. Refer to Error Codes section at https://www.cox.com/residential/suppor... Mar 12 05:28:12 22 north courieresmtp: id=00000000005DC124.000000005E69B7FA.00002EE1,from=<ab...@ta...>,addr=<ab...@co...>: 250 2.0.0 CFS6jR7NG1lJtCFS7jw136 mail accepted for delivery Mar 12 05:28:19 22 north courieresmtp: id=00000000005DC0D3.000000005E69B801.00002F5A,from=<ab...@ta...>,addr=<ab...@co...>: 452 4.1.0 <ab...@ta...> server temporarily unavailable. Refer to Error Codes section at https://www.cox.com/residential/suppor... Mar 12 05:30:17 22 north courieresmtp: id=00000000005DC153.000000005E69B85E.00003842,from=<ab...@ta...>,addr=<ab...@co...>: 250 2.0.0 CFU6jGmuuLxHeCFU8jVN9a mail accepted for delivery Mar 12 05:49:58 22 north courieresmtp: id=00000000005DC0CB.000000005E69B5D4.000005E3,from=<ab...@ta...>,addr=<ab...@co...>: 250 2.0.0 CFnAjNjtJarJHCFnBjoW75 mail accepted for delivery Mar 12 05:50:01 22 north courieresmtp: id=00000000005DC0F8.000000005E69B5E1.0000070F,from=<ab...@ta...>,addr=<ab...@co...>: 452 4.1.0 <ab...@ta...> server temporarily unavailable. Refer to Error Codes section at https://www.cox.com/residential/suppor... Mar 12 05:50:09 22 north courieresmtp: id=00000000005DC101.000000005E69B5ED.00000813,from=<ab...@ta...>,addr=<ab...@co...>: 250 2.0.0 CFnKj8X46OFPgCFnMj8Cbn mail accepted for delivery Mar 12 05:55:03 22 north courieresmtp: id=00000000005DC0F8.000000005E69B5E1.0000070F,from=<ab...@ta...>,addr=<ab...@co...>: 250 2.0.0 CFs5jFkWeooUgCFs7jNbHM mail accepted for delivery Mar 12 05:58:06 22 north courieresmtp: id=00000000005DC0A6.000000005E69B7F3.00002E1A,from=<ab...@ta...>,addr=<ab...@co...>: 250 2.0.0 CFv0jRPVT1lJtCFv3jw8xu mail accepted for delivery Mar 12 05:58:20 22 north courieresmtp: id=00000000005DC0D3.000000005E69B801.00002F5A,from=<ab...@ta...>,addr=<ab...@co...>: 452 4.1.0 <ab...@ta...> server temporarily unavailable. Refer to Error Codes section at https://www.cox.com/residential/suppor... Mar 12 06:03:24 22 north courieresmtp: id=00000000005DC0D3.000000005E69B801.00002F5A,from=<ab...@ta...>,addr=<ab...@co...>: 250 2.0.0 CG09jRT7d1lJtCG0BjwAd6 mail accepted for delivery Having enabled ulog on mariadb, I see that sporadically Courier is able to run a two-message sessions (lasting 70~80 secs), by the following detail: MariaDB [ulog]> select DATE_FORMAT(FROM_UNIXTIME(flow_start_sec), '%b %e %H:%i:%s') AS start, DATE_FORMAT(FROM_UNIXTIME(flow_end_sec), '%H:%i:%s') AS end, flow_end_sec - flow_start_sec AS secs, orig_ip_saddr_str, orig_ip_daddr_str from ct where orig_ip_daddr_str in ('52.73.137.222', '35.162.106.154', '34.212.80.54', '18.209.118.139', '18.209.118.139') ORDER BY flow_start_sec; +------------------+----------+------+-------------------+-------------------+ | start | end | secs | orig_ip_saddr_str | orig_ip_daddr_str | +------------------+----------+------+-------------------+-------------------+ | Mar 12 05:06:25 | 05:07:46 | 81 | 62.94.243.226 | 35.162.106.154 | | Mar 12 05:08:40 | 05:09:05 | 25 | 62.94.243.226 | 35.162.106.154 | | Mar 12 05:08:46 | 05:09:03 | 17 | 62.94.243.226 | 52.73.137.222 | | Mar 12 05:08:50 | 05:09:13 | 23 | 62.94.243.226 | 18.209.118.139 | | Mar 12 05:08:55 | 05:09:13 | 18 | 62.94.243.226 | 34.212.80.54 | | Mar 12 05:08:59 | 05:09:21 | 22 | 62.94.243.226 | 35.162.106.154 | | Mar 12 05:09:04 | 05:09:33 | 29 | 62.94.243.226 | 35.162.106.154 | | Mar 12 05:09:09 | 05:09:25 | 16 | 62.94.243.226 | 34.212.80.54 | | Mar 12 05:09:14 | 05:09:35 | 21 | 62.94.243.226 | 18.209.118.139 | | Mar 12 05:09:17 | 05:09:38 | 21 | 62.94.243.226 | 35.162.106.154 | | Mar 12 05:09:21 | 05:09:46 | 25 | 62.94.243.226 | 35.162.106.154 | | Mar 12 05:09:26 | 05:09:46 | 20 | 62.94.243.226 | 52.73.137.222 | | Mar 12 05:09:31 | 05:09:45 | 14 | 62.94.243.226 | 35.162.106.154 | | Mar 12 05:09:35 | 05:10:57 | 82 | 62.94.243.226 | 52.73.137.222 | | Mar 12 05:13:46 | 05:14:04 | 18 | 62.94.243.226 | 34.212.80.54 | | Mar 12 05:13:55 | 05:14:12 | 17 | 62.94.243.226 | 52.73.137.222 | | Mar 12 05:14:04 | 05:14:22 | 18 | 62.94.243.226 | 34.212.80.54 | | Mar 12 05:14:14 | 05:14:32 | 18 | 62.94.243.226 | 35.162.106.154 | | Mar 12 05:14:21 | 05:14:42 | 21 | 62.94.243.226 | 34.212.80.54 | | Mar 12 05:14:31 | 05:14:57 | 26 | 62.94.243.226 | 52.73.137.222 | | Mar 12 05:17:34 | 05:17:56 | 22 | 62.94.243.226 | 35.162.106.154 | | Mar 12 05:17:48 | 05:18:13 | 25 | 62.94.243.226 | 18.209.118.139 | | Mar 12 05:17:52 | 05:18:08 | 16 | 62.94.243.226 | 52.73.137.222 | | Mar 12 05:17:56 | 05:18:12 | 16 | 62.94.243.226 | 35.162.106.154 | | Mar 12 05:18:00 | 05:18:16 | 16 | 62.94.243.226 | 18.209.118.139 | | Mar 12 05:18:04 | 05:18:26 | 22 | 62.94.243.226 | 18.209.118.139 | | Mar 12 05:18:07 | 05:18:22 | 15 | 62.94.243.226 | 34.212.80.54 | | Mar 12 05:18:11 | 05:18:27 | 16 | 62.94.243.226 | 35.162.106.154 | | Mar 12 05:18:16 | 05:18:38 | 22 | 62.94.243.226 | 18.209.118.139 | | Mar 12 05:18:19 | 05:19:03 | 44 | 62.94.243.226 | 35.162.106.154 | | Mar 12 05:19:52 | 05:20:14 | 22 | 62.94.243.226 | 35.162.106.154 | | Mar 12 05:19:56 | 05:20:18 | 22 | 62.94.243.226 | 18.209.118.139 | | Mar 12 05:20:00 | 05:20:17 | 17 | 62.94.243.226 | 35.162.106.154 | | Mar 12 05:20:05 | 05:20:21 | 16 | 62.94.243.226 | 34.212.80.54 | | Mar 12 05:20:09 | 05:20:26 | 17 | 62.94.243.226 | 18.209.118.139 | | Mar 12 05:20:12 | 05:20:30 | 18 | 62.94.243.226 | 35.162.106.154 | | Mar 12 05:20:17 | 05:20:42 | 25 | 62.94.243.226 | 35.162.106.154 | | Mar 12 05:22:43 | 05:23:09 | 26 | 62.94.243.226 | 52.73.137.222 | | Mar 12 05:22:56 | 05:23:20 | 24 | 62.94.243.226 | 35.162.106.154 | | Mar 12 05:23:04 | 05:23:25 | 21 | 62.94.243.226 | 35.162.106.154 | | Mar 12 05:23:11 | 05:23:28 | 17 | 62.94.243.226 | 52.73.137.222 | | Mar 12 05:23:19 | 05:24:42 | 83 | 62.94.243.226 | 35.162.106.154 | | Mar 12 05:25:09 | 05:25:24 | 15 | 62.94.243.226 | 52.73.137.222 | | Mar 12 05:25:17 | 05:26:40 | 83 | 62.94.243.226 | 34.212.80.54 | | Mar 12 05:27:54 | 05:28:13 | 19 | 62.94.243.226 | 52.73.137.222 | | Mar 12 05:28:09 | 05:28:35 | 26 | 62.94.243.226 | 34.212.80.54 | | Mar 12 05:30:13 | 05:31:34 | 81 | 62.94.243.226 | 34.212.80.54 | | Mar 12 05:49:56 | 05:50:17 | 21 | 62.94.243.226 | 52.73.137.222 | | Mar 12 05:50:05 | 05:51:20 | 75 | 62.94.243.226 | 35.162.106.154 | | Mar 12 05:55:01 | 05:56:15 | 74 | 62.94.243.226 | 52.73.137.222 | | Mar 12 05:58:02 | 05:58:39 | 37 | 62.94.243.226 | 34.212.80.54 | | Mar 12 06:03:21 | 06:04:35 | 74 | 62.94.243.226 | 34.212.80.54 | +------------------+----------+------+-------------------+-------------------+ 52 rows in set (0.01 sec) Best Ale -- |
