Re: SPF support in opendkim?

From: Alessandro Vesely <>
Date: Sat, 13 Aug 2011 18:58:32 +0200

On 12.08.2011 01:20, Murray S. Kucherawy wrote:
>> -----Original Message-----
>> From: Steve Fatula []
>> Sent: Thursday, August 11, 2011 2:54 PM
>> To: Murray S. Kucherawy; Opendkim
>> Subject: Re: SPF support in opendkim?
>> On higher volume postfix servers, all those processes being separate
>> significantly reduces emails per hour one can handle.
> I'd like to see some data to back that up. In the analysis I've done,
> both of them spend most of their time waiting for DNS replies, not
> cranking through analysis steps or talking back and forth with postfix.
> And if that's true, then combining the two into one won't save you much of
> anything in the long run; the I/O delay of having to talk to two filters
> instead of one will be noise compared to how long you're waiting for DNS
> servers on far away networks to answer your queries for SPF policies and
> DKIM keys.

Although I cannot produce supporting data, I have the same hunch that DNS is
the bottleneck. An SPF filter which does not reject right away on failures
can start queries at an earlier SMTP stage than DKIM, and thus take less time
for each message. Consider an SMTP extension that provides for declaring
DKIM's domain(s) and selector(s) before sending DATA. Could that better the
throughput noticeably?

Just conjecturing...
Received on Sat Aug 13 2011 - 16:58:52 PST

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