On Sunday 15 August 2004 11:26, Malcolm Kay wrote: > On Sunday 15 August 2004 10:40, Chuck Swiger wrote: > > Malcolm Kay wrote: > > [ ... ] > > > > > Thanks guys for the responses -- this really looks the way to go. > > > > > > Does anyone know how sendmail distinguishes between: > > > reject=451 4.1.8 Domain of sender address ................ does not > > > resolve reject=553 5.1.8 .......... Domain of sender address > > > .............. does not exist It seems the former is to be interpreted > > > as a 'temporary' condition while the latter is to be interpreted as > > > 'permanent' (and is by default deleted by fetchmail)? > > > > Sendmail pays attention to the return value from doing DNS queries. If > > sendmail receives an NXDOMAIN response, it treats that as a permanent, > > 5xx failure code. If sendmail gets a timeout/TRY_AGAIN, it will return a > > 4xx temp failure. > > This sort of takes us back one more level -- how does the DNS service > decide between responding with NXDOMAIN and a timeout/TRY_AGAIN? And does > the difference have any real significance? > > > It's not clear to me why this would matter if your ISP is the one running > > the mailserver: they aren't accepting the message in either case, which > > ought to mean that fetchmail will never see it. > > None of it is particularly clear to me -- but apparently my ISP's server is > not rejecting these messages. > > If all mail servers rejected these messages it would seem to me to make the > spammers endeavours rather pointless. >
Perhaps I've not made it clear that the above reject messages appear in the maillog on my local machine as a consequnce of fetchmail reposting the messages to local sendmail. Malcolm _______________________________________________ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
