Re: [apps-discuss] draft-santos-smtpgrey-02: SMTP Service Extension for Greylisting Operations

[Derek Diget <[e-mail]>]

On Feb 2, 2014 at 22:57 -0800, Ned Freed wrote:
=>> On Sat, Feb 1, 2014 at 10:39 AM, Hector Santos <[e-mail]> wrote:
=>> > For our own implementation and deployments of WCSMTP.
=>> >
=>> > No collections from other packages was made from a client standpoint.
=>
=>> Does anyone else have current or planned implementations of this draft
=>> they'd like to discuss?
=>
=>We see greylisting as something best done by a milter, so we're unlikely to
=>implement direct support in our MTA. That said, a milter has the ability to set
=>the SMTP response string to anything it wants. The only problem a milter would
=>have is changing the EHLO response to include the GREYLISTING extension. AFAIK
=>that is not a milter capability. We have a way to do that outside of milter but
=>I don't know if other milter-supporting MTAs do.

FYI, we use Ned's software and have the following defined in our 
ORIG_MAIL_ACCESS mapping (based on the Comms Suite Greylisting Wiki page 
at 
<https://wikis.oracle.com/display/CommSuite/Implementing+Greylisting+by+Using+MeterMaid>)

! Check the source IP address only using the first three octets in the 
! string passed to MeterMaid, sender (canonicalized via X-CORRESPONDENT 
! mapping recursion lookup), and recipient in MeterMaid's greylist 
! table.
!
! If the call to greylisting() returns success, then Messaging Server 
! should return a temporary rejection. If the call fails, then the 
! greylisting check has passed and other access control checks can continue

  TCP|$@*|$@*|$D*.$D*.$D*.$@*|$@*|SMTP$@*|MAIL|tcp_mx|*|l|*|true $C$[IMTA_LIB:check_metermaid.so,greylisting,greylist,$0.$1.$2|$|X-CORRESPONDENT;$3||$4]$N$X4.7.1|Temporary$ greylist$ rejection$ -$ retry$ in$ retry=00:03:00$ $E


Which causes the following SMTP response:

  451 4.7.1 Temporary greylist rejection - retry in retry=00:03:00 : RECIPIENT@RECIPIENT-DOMAIN


I don't have any data on how many clients then following our suggestion.


I know we are less than a grain of sand on the mail flow beach, but 
thought that I would speak up as one receiver. :)

-- 
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Derek Diget                            Office of Information Technology
Western Michigan University - Kalamazoo  Michigan  USA - www.wmich.edu/
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