--On 9 July 2009 09:54:31 -0400 Adam Tauno Williams <adam@xxxxxxxxxxxxxxxx> wrote: >>> Ian Eiloart wrote, at 07/09/2009 05:39 AM: >>>> Except that the sieve server ought to be on the border MTA, so that the >>>> user can tell the server to reject the message at SMTP time. >>> That's not feasible for mail with multiple recipients. >> It is if your rule is to reject all email from a specific sender. > > No, because the MTA either accepts or rejects a message [in > connection]. Not true. The MTA can decide *per recipient* whether to accept mail from a specific sender. It's true that the MTA hasn't seen the message content at this point, but it does have enough information to determine - for example - whether the sender is a member of a mailing list, or is on a recipient's blacklist or whitelist. We do a lot of that. Exim, for example, can do this in its ACLs. It doesn't have a built in SIEVE facility at this stage, but certainly can consult recipient specific blacklists. It can even be built with a perl interpreter, so you could check for sender conditions in SEIVE scripts. > If a message is sent to userX and userY and userX has > SIEVE set to reject the message and userY does not then the MTA has to > receive the message in order to deliver it to userY. And the MTA > would have to check every recipient's SIEVE script. Sure, there are some content dependent conditions that could not be tested at this stage. In principle, they could be ignored for the moment. There probably aren't any SIEVE implementations that do what I suggest, and the implementations wouldn't be simple, but there's no principled reason that it shouldn't. > Then what about > delivery to an alias that expands to multiple users? > Mail delivery > just isn't that simple. -- Ian Eiloart IT Services, University of Sussex 01273-873148 x3148 For new support requests, see http://www.sussex.ac.uk/its/help/ ---- Cyrus Home Page: http://cyrusimap.web.cmu.edu/ Cyrus Wiki/FAQ: http://cyrusimap.web.cmu.edu/twiki List Archives/Info: http://asg.web.cmu.edu/cyrus/mailing-list.html
