> On Feb 20, 2017, at 7:19 PM, Wietse Venema <wie...@porcupine.org> wrote:
>
> Why should Postfix abandon a connection that replies with 4xx to a
> recipient? How is this different from sending a multi-recipient
> message?
I guess because hard error limits may induce tarpit controls on the
receiving side?
Mind you, a server doing greylisting should probably not employ tarpit
controls. Another reason may be that once a remote "421" disconnect is
triggered by too many consecutive errors, we may (begin to) throttle the
destination.
As you point out, with greylisting, a multi-recipient message to O(100)
recipients may run into issues rather similar to the ones just reported
with connection re-use...
--
--
Viktor.
