Re: We need an IETF BCP for GREY LISTING
2011-10-18 04:25:58
Keith Moore wrote:
On Oct 17, 2011, at 12:25 PM, Hector wrote:
It seems there is a majority consensus that a IETF document for
Greylisting would be a worthy effort.
I'm still unconvinced. I haven't seen any evidence to support this at
all.
hmmm, unless I mis-read people's input, many people contributing to the
thread recognized there are issues and most have indicated a note that a
IETF document for greylisting would be a good thing.
I believe you cited an interest in an SMTP extension for a retry hint.
I mentioned how it could be done, but also expressed concern that it might
not be worth the trouble... also I said that greylisting wasn't the reason
for such an extension.
I am in complete agreement with Keith's observations. To further elaborate
the issue of formalizing 4xx return codes is NOT an issue with Greylisting,
and this is not the context to address such extensions. If SMTP were to
include such extensions, it should be a general feature, and not something
perceived to be tied with GL.
Now, with respect to Greylisting - precisely what existing problem are we
trying to solve? 4xx return codes are not a greylisting issue. The few
problems that were mentioned to me seem to be configuration related, and
really not subject to an RFC. Sites that either run too short MTA retry
times (30 seconds for a retry for example) will always run into problems,
regardless if they are trying to connect to a remote server that has them on
a temporary greylist, or any other site that is inaccessible for some period
of time. Progressive backoff strategies were put in place precisely for
this reason - but some care needs to be taken to choose reasonable timing
values.
Greylisting sites that configure timeout windows that greatly exceed the
norm for remote MTA retry times (hours or more for instance) are also
improperly configured and will not play well with MTA's with reasonable
backoff times.
A BCP that describes various queuing strategies in terms of retry times, and
the relationship between MTA timing and Greylist delay windows might be a
good thing for a BCP. It's really not all that difficult, however
sometimes putting these things into writing can help new administrators.
The BCP can then formalize what the community considers "reasonable" values
for MTA's and GL running servers.
Anything else I'm really at a loss to understand what we are trying to fix.
Greylisting for the most part works and other than the queue timing issues
above seems largely to be a non-issue.
Best Regards,
-- Tim
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- Re: We need an IETF BCP for GREY LISTING, (continued)
- Re: We need an IETF BCP for GREY LISTING, Paul Smith
- Re: We need an IETF BCP for GREY LISTING, Keith Moore
- Re: We need an IETF BCP for GREY LISTING, Richard Kulawiec
- Re: We need an IETF BCP for GREY LISTING,
Tim Kehres <=
- Re: We need an IETF BCP for GREY LISTING, Rolf E. Sonneveld
- Re: We need an IETF BCP for GREY LISTING, Keith Moore
- Re: We need an IETF BCP for GREY LISTING, Frank Ellermann
- Re: We need an IETF BCP for GREY LISTING, Keith Moore
- RE: We need an IETF BCP for GREY LISTING, Rosenwald, Jordan
- Re: We need an IETF BCP for GREY LISTING, Keith Moore
- RE: We need an IETF BCP for GREY LISTING, Rosenwald, Jordan
- Re: We need an IETF BCP for GREY LISTING, Dave CROCKER
- Re: We need an IETF BCP for GREY LISTING, Derek J. Balling
- Re: We need an IETF BCP for GREY LISTING, Keith Moore
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