Karl O. Pinc:
> Hello,
>
> I just had a situation where the sending postfix
> (me) uses greylisting, and the receiving postfix
> is using address_verify_sender.
>
> The greylisting generates a 450 response to
> the address_verify_sender query triggered by
> the initial email. The receiving postfix
> appears to be caching this as a failure,
> and not retrying the verify sender for some time.
> During that period the sending postfix retries
> mail delivery, but continues to get a 450
> from the receiver until address_verify_negative_refresh_time
> runs out.
You can disable Postfix's negative reply caching in main.cf, but
you do so at your own risk. The default setting caches the reply
and therefore guarantees that infinite loops will be broken.
Wietse
> I believe that address_verify_sender should not cache
> 4xx responses as failures. Then when the sender retries
> the receiver will also retry it's address_verify_sender,
> the greylisting should allow the query, and the mail
> would then be delivered. (This assumes that the
> greylisting is configured on the sending site
> in a fashion that would not
> block a site with the same retry policies as the
> sending site. This seems a safe assumption.)
>
> Being the sender, I do not have a postfix version
> number for verify.
>
> Regards,
>
>
> Karl <kop AT meme DOT com>
> Free Software: "You don't pay back, you pay forward."
> -- Robert A. Heinlein
>
>
>
|
