Author: Chad Leigh Date: To: exim users Subject: Re: [exim] require_verify = sender + RBLs - clarification on the
How-to
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.
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
---
Chad Leigh -- Shire.Net LLC
Your Web App and Email hosting provider
chad at shire.net
