Graeme Fowler wrote: > On Fri, 2010-06-11 at 13:09 -0400, W B Hacker wrote: >> That's quite elegant! (Given one understands '0' means 'infinity' here) > > Thanks. For "Understanding" replace with "the documentation for this > option states that" :) > >> But is it 'cheap'? > > Not as "cheap" as not doing the lookup, obviously. And if you had a > bazillion hosts/netblocks in your hostlist it would probably be quite > slow; but if you had that, you'd be doing it wrong. > > The fact that it acts before any SMTP processing is done makes it pretty > lightweight. Given that recipient verification further down the > transaction will cost many times more resources, deferring connections > before you've even sent a banner is worth a lot. > > So yes - it's "cheap". > > Graeme > > >
Here's another possible use: Givens: - a possible houseful of guests, coffee-shoppers, bookstore or airport WiFi hot spot, or a business office full of folks who might attempt to *submit outbound* simultaneously from the same shared IP: - said IP may be dynamic, unsuited to direct entry into a hostlist as an IP - but the port (587) is not dynamic - shared link may be slower than a local, if not international backbone, ergo time-on-teat longer and overlap probability higher Might there be a value in granting an exemption for simultaneous connections from one IP to the *submission* port (587) and wildcarding the (often dynamic) IP? ?? Bill -- ## List details at http://lists.exim.org/mailman/listinfo/exim-users ## Exim details at http://www.exim.org/ ## Please use the Wiki with this list - http://wiki.exim.org/
