Vernon Schryver <vjs@xxxxxxxxxxxxxxxxxxxx> wrote: > > I know of many millions of spam that are filtred during the DATA command > every day, and I don't claim to know about any really big sites. > > The only problems are: > - local administrative choices that keep bastion SMTP servers ignorant > of per-user filter preferences This is a feature, not a problem. If the end user wants a filtering process individualized that much, s/he should choose to use a SMTP server which agrees to do so. > - filtering at the DATA command requires either (1) rejecting for > all or no targets or (2) accepting for all targets and siliently > discarding the message for those targets that want it filtered. Alternatively, the receiving SMTP server could reject any multiply- addressed email. Is it actually that unreasonable to apply the most-restrictive filtering rules in the case of multiply-addressed email? (Silently discarding _is_ a bad idea, when done by the SMTP server itself. IMHO, it's better to mark for later discard -- which actually could be done in such a way as to mark only for those recipients who requested the more restrictive filtering.) > In theory the second problem could be fixed if the DATA command could > accept a vector of 250-OK/4yz-try-later/5yz-fatal responses, one for > each target named with a Rcpt_To command. In practice the spam problem > will be solved one way or another long before such a protocol change > would be sufficiently widely deployed to matter. Agreed: that radical a change in SMTP wouldn't percolate through quickly enough. -- John Leslie <john@xxxxxxx>