Am 03.06.2014 11:39, schrieb st...@thornet.co.uk: >> What sort of "broken" clients are these that don't use real email servers, >> and how do you know they are broken? They could very well be waiting for >> some time to pass before retrying again (and there is some kind of a >> system >> for these intervals. It's not as if the standard protocol is to resend all >> of your undelivered email every 5 minutes...) > > After 24 hours the missing mail still hasnt arrived. So they must have a very > long retry period!
what are you discussing here? * the SMTP protocol specifies temporary and permanent errors * in case of temporary the client MUST retry * if it does not it's broken and not your problem * if it does the retry period is the senders business * typically each retry adds more time before try again * the frist retry normally is within minutes it is *not* your problem if the sender is broken in that case he is *not* only broken in case of mails to you if the sender don't respect 4xx repsones he has *massive* problems all over the world when the destination is using greylisting because greylisting *by definition* always rejetcs the first delivery with a 4xx response just because it catchs any non-MTA and spam zombies so don't waste your time solve *your* problems and not the ones of other people it's the problem of the sender to *shout at his* server admin why he has a non working MTA or re-consider using a MTA at all instead of broken software try to deliver only once the sender MUST NOT expect that every delivery is successful at the first try because that's not how the internet is supposed to work - internet services are supposed to deal with temporary problems and SMTP is *well desigend* to handle that perfectly
