On Monday, March 5, 2012, 12:06:09, Wietse Venema wrote: > Rod Dorman: >> On Monday, March 5, 2012, 09:53:31, /dev/rob0 wrote: >> > ... >> > Another WAG: maybe your ISP's upstream provider got tired of >> > complaints and implemented this redirection upstream. This would >> > explain why the ISP would not know. >> >> I would be horrified is this turned out to be the cause. >> >> Without deep packet inspection there would be no way to distinguish >> between SMTP packets originating from the ISP's MTA vs. his MTA. > > Are you thinking of an ISP with the entire network behind a NAT router?
No (that would be weird :-) rob0 got my point (which I guess I shudda been clearer in making) being anything upstream would have to somehow know the set of IP addresses to allow to pass. In retrospect it could be maintained manually by the downstream ISP telling the upstream ISP whenever it changes which servers to allow but it would be an awfully wimpy ISP to accept those conditions from their upstream provider. -- r...@polylogics.com "The avalanche has already started, it is too Rod Dorman late for the pebbles to vote." - Ambassador Kosh
