Bernd Wurst writes:
Hi Sam.It's ridiculous. I'm not a native english speaker, perhaps this is the reason that you are not willing to understand the key point. Am Mittwoch, 9. März 2011, um 00:12:49 schrieb Sam Varshavchik: > Bernd Wurst writes: > > in this case, is blocked via greylisting by the recipient. > With greylisting, a connection to the server gets successfully established, > but, from the sender's perspective, the delivery attempt fails. Perfect. This is right for the FIRST ATTEMPT. Greylisting is only an example for any reason why the very first attempt fails.
It is right for any attempt. Each delivery attempt is an independent event.
> The reasons for the delivery failures are irrelevant. To attempt to > immediately try some other server to deliver the unwanted mail, is > considered to be, at least rude, if not abusive. Rather, it is expected > that the sender would wait, and try again later. That's a perfect strategy. But this second try is never ever done via IPv4 again.
I see no evidence of that happening. There is nothing in the code that discriminates between IPv4 and IPv6 addresses.
> Any attempt to use another IP address, being IPv4 or IPv6, only occurs if > there was a failure to establish a TCP connection. That is not true. When a network problem ocures with IPv6 (routing error), no TCP connection could be established. Courier just gives up and does not try IPv4. That's what I'm trying to say.
I see no evidence of that. Once the list of IP addresses for a domain is obtained, the connection attemps are made in a compleletely agnostic manner. There is no difference in treatment between IPv4 and IPv6 addresses.
First try CAN establish a TCP connection and then is blocked by greylisting. All further tries run into a timeout because IPv6 is broken. There is no further try on the IPv4 address.
I don't know what to tell you. Each delivery attempt, five minutes apart, is executed by a completely different process, that has no knowledge of what happened in some unrelated process, five minutes earlier.
A courieresmtp client persists for no longer than a minute, in order to recycle connections. Each delivery attempt you logged was from a different process, each.
pgpRILVoS5AkQ.pgp
Description: PGP signature
------------------------------------------------------------------------------ Colocation vs. Managed Hosting A question and answer guide to determining the best fit for your organization - today and in the future. http://p.sf.net/sfu/internap-sfd2d
_______________________________________________ courier-users mailing list courier-users@lists.sourceforge.net Unsubscribe: https://lists.sourceforge.net/lists/listinfo/courier-users
