In message <3j7sdd1mnszb...@spike.porcupine.org>, wie...@porcupine.org (Wietse Venema) wrote:
>Ronald F. Guilmette: >> >> In message <542c35a7.3050...@rhsoft.net>, >> "li...@rhsoft.net" <li...@rhsoft.net> wrote: >> >> >Am 01.10.2014 um 19:04 schrieb Ronald F. Guilmette: >> >> What would happen in such a case? Would inbound e-mail start to >> >> back up horribly, as Postfix waited for DNS responses that were >> >> not forthcoming? >> > >> >no - no answer is just no answer and mail goes through >> >> Yeabut, how sloooooooooly? > >See "man 5 resolver" for timeouts, retry counts, etc. Thank you. I am aware of the general retry scheme. Nominally, I believe that there is one try and three retries, starting at a five second delay and doubling that for each successive retry. So, 5+10+20+40 = 1.25 minutes, in case the server you are querying is down. No? But clients of a typical resolver library (e.g. Postfix) may optionally request either more or fewer retries. No? So I was asking what Postfix does. Also, I was sort-of indirectly asking whether or not Postfix has any in-built mechanism that might automagically spot malfunctioning blacklist servers and disable their further use, you know, in order to prevent inbound stuff from getting all backed up.
