On Sat, 24 Dec 2005, Giuliano Gavazzi wrote: [quoting spamcop:] > Although bounces are required, it is possible to avoid the situation > under which they are required (see above). So they aren't really > required unless you have already 'painted yourself into a corner.'" > > so, either you check recipient by attempting the delivery while > still at SMTP phase (a nightmare with timeouts) or you forbid > forwarding (an approach not totally without sense) or you send > errors to postmaster (a nightmare on busy sites).
It all sounds plausible, but I'm afraid that our users would not stand for a mail system which refused to implement forwarding, and vacation responses. No matter how carefully we admins try to convince them otherwise ;-) We make every effort to avoid accepting spam in the first place, as well as inhibiting the vacation response at the slightest indication of bulk mail, mailing lists, etc. etc., anything that isn't a bona fide personal email to the individual (I have argued that we should also inhibit the vacation response at a spamassassin spam-suspect score of 5.0, instead of at the rejection level of 8.0, although this hasn't actually been implemented). But, once we have accepted an item, some users will, as I say, have set their options for forwarding and/or for a vacation response. Verifying the forwarding address at SMTP time is all very well, but there are also cases where we have accepted the item as non-spam, and we only get to discover that the target MTA rates the content as spam when we try to forward it. There can be other plausible circumstances where we accept an item for forwarding, and only afterwards discover that we are unable to deliver it. At this point, we're required by the specs to compose a non-delivery report, and we can't really afford to have each and every one of those vetted by the postmaster before it goes out. So yes, there will be some low level of bogus bounces from us, under those hopefully limited number of circumstances. We also have the situation where users have accounts at remote sites with forwarding to us. Whenever we decide to reject items from those forwarded accounts, the remote site is supposed to be composing a non-delivery report - but that's done under the responsibility of the forwarding site, and IMHO can't really be blamed on us. I've been flamed on more than one occasion for rejecting unwanted items (such as forwarded viruses, which caused the forwarding site to bounce the virus to an innocent party and get themselves blacklisted), but I'm afraid I've no sympathy for the idea that we're somehow morally compelled to accept crud from these forwarding sites in order to help them stay out of blacklists. best regards and seasons greetings -- ## List details at http://www.exim.org/mailman/listinfo/exim-users ## Exim details at http://www.exim.org/ ## Please use the Wiki with this list - http://www.exim.org/eximwiki/
