Chad Leigh -- Shire.Net LLC wrote: > On Oct 21, 2006, at 7:44 AM, Alon wrote: > > >>Third, You made the point/case that: >> >>"Some very large / major ISP's do not have usable DNS records for >>their >>'pools' of servers." >> >>NOW that's something to be concerned about. Since I'm running a shared >>hosting environment with folks from >>all over the world, it is very likely that some of them are >>interacting with >>servers that are indeed poorly maintained/configured. >>That is a valid reason by itself why NOT to use this feature. >>I can lecture to my clients that they SHOULD instruct their buddies >>out >>there to lecture their service providers... and yeah..going >>back to reality this is never going to happen.
A finite, but very large number of .com and .net domains are 'parked' with Network Solutions. For a very reasonable fee, NetSol also provide email service for those domains. Thousands of individuals, hundreds, if not thousands of SME, and a few larger businesses who have not gotten a round tuit w/r migrating to ther server use this service. Some months ago this was found to be problematic for our clients. We start with host -v, dig, and whois to discover separate inbound pools. We ended with digging thru the reject log to find 'stealth' servers used for *outbound* that: - had imprpper or NO DNS entry, - improper or missing PTR, - HELO mismatched, and to the point where a HELO might return a different verdammt *.tld*, (.net and .com mixed) as well as different domain, not to mention the mismatched prefixes used. We had to 'VIP-list' that mess, as a simple whitelist was not good enough. They broke everything that could be broken but TCP/IP itself. :-( > > > I have verify sender with callout and we have customers all over the > world. We have had very little mail loss that is verifiable and when > we do, almost 100% of the time we were able to get the offending > server to "fix" itself to become conformant the RFCs regarding DSN > and <> (every one that has failed for us has been someone who rejects > <> sender as spam). We are a small provider and are not the best > example due to how small we are compared to big mail providers but it > has not been a real issue with us that it has disrupted mail service > or caused problems. A handful of times we have pointed out to the > offending senders that their servers are misconfigured (we always > take the angle that we cannot accept mail from people who do not > accept an appropriately sent DSN) and most of the time they have > fixed their problem. We did have to whitelist one person whose > provider is generally clueless about almost everything and one > provider wouldn't even talk to us as we were not his customer... Our > users/customers have greatly appreciated the service as well. We are > always trying to improve our spam checks so as to not have to do a > callout but the callout does greatly reduce the amount of spam we > have to accept and deliver. > > Chad > NetSol doesn't care about RFC's or DNS correctness or smtp manners. They don't *have to*. (more's the pity, but what's a Mother to do?) Bill -- ## 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/
