Dnia 27.02.2023 o godz. 21:38:01 Luke via mailop pisze: > Second factor (and the main factor) is our customers. We send 32 deferral > events over the course of 72 hours to our customers' data warehouses for > each message that reaches max queue time. That's 32 events they are > consuming and storing as well. The customers, not being RFC-reading (and > RFC-writing) mail operators like the group here, ask us why we keep > retrying for so long on messages we know will never deliver. To the > customer these deferral events are just a nuisance.
Do I understand correctly that you send 32 deferral notices within 72 hours *per each message*? That seems nonsense to me. The standard behavior of the good old sendmail (inherited by many other MTAs as default setting) was to send *one* deferral notice if the message was not delivered within the first 4 hours, and then only send a final bounce when the message reaches max queue time. Why did you modify it so heavily? As for the not retrying on 4xx: If it is marketing mail only, I agree that basically nobody gets hurt (or even quite the opposite ;)) if some of the mail doesn't get delivered. It's worse when it comes to transaction mail (like password reset links, receipts from Internet shops etc.) that is not retried. And I have seen quite a few of these, from big senders, *not* being retried on 4xx (although if I remember correctly, not from Sendgrid). This is much worse. Another nonsense thing for me is that some senders - again, mostly the big ones - retry almost *immediately* (often from a different IP address) if they encounter a 4xx, and after a few such unsuccessful retries (within only a few minutes) they eventually give up. I wonder what had in mind someone who designed it that way? In a very broad sense, 4xx means some transient problem on the receiving side that will eventually get fixed, and then the mail will be accepted. But fixing any problem requires time. Did someone who designed this behavior expect that the problem will "miraculously" disappear if they retry immediately a few times? -- Regards, Jaroslaw Rafa r...@rafa.eu.org -- "In a million years, when kids go to school, they're gonna know: once there was a Hushpuppy, and she lived with her daddy in the Bathtub." _______________________________________________ mailop mailing list mailop@mailop.org https://list.mailop.org/listinfo/mailop
