On 2023-02-28, Jaroslaw Rafa via mailop <mailop@mailop.org> wrote: > 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?
Maybe worth pointing that people do greylisting, and with greylisting it's helpful to retry quite soon. Immediately isn't useful, but within five minutes is. (I personally have one-minute greylisting set.) I often see immediate retries to the next MX, which of course is a reasonable thing to do (and often bypasses my greylist, owing to the way I do it - I view this as a feature:). _______________________________________________ mailop mailing list mailop@mailop.org https://list.mailop.org/listinfo/mailop
