[milters] Archive

Lists Index Date Thread Search

Article: 533
From: Michael Elliott
Date: 2005-05-02 15:33:18 -0400
Subject: [SIQ] 001 Re: Re: new feature request

Removal...........: milters-request@milter.info?subject=remove
More information..: http://www.milter.info/#Support
--------------------------------------------------------

> 
> Based on this I've just added a new option, -n, to not grey list the 
> null address.
> 
> However, auto white listing just the RCPT as a future sender of a reply 
> would certainly be a worth while enhancement, but in the case of 
> call-backs its problematic. You would have to auto white list the IPs of 
> all the MXes of each RCPT domain in the off chance that they perform a 
> call-back.
> 
> Now consider the following example:
> 
> 	MAIL FROM:<localuser@localmx.com>
> 	RCPT TO:<user@aol.com>
> 

Here is an easier method.  Double lookup.  When -k = MAIL:RCPT:IP.
Greylist entries in the database are checked first as MAIL:RCPT:IP tuple, and
then as MAIL:RCPT.  Any entry added to the database from a local user would 
add the MAIL:RCPT:IP, and RCPT:MAIL as the auto whitelisting.

A more complicated version would be one that upgrades the RCPT:LOCAL to RCPT:LOCAL:IP.
The way to do that is:
  IF match was on RCPT:MAIL, and mail reaches the smfi_eof or smfi_body stage, 
    upgrade RCPT:MAIL to RCPT:MAIL:IP since it is a full incoming piece of mail.
    A new message from localuser would trigger a new RCPT:MAIL to be generated.
  else
    the message only went to smfi_rcptto stage, and is a grey listing check, so
    change nothing.
Use a short time to live on the RCPT:MAIL entries, as they are expected to 
do their callback in seconds to hours.  There could be a intermediate MX that 
may be greylisted in the middle, so one has to allow for multiple grey listing
delays.

I personally had to turn down the database -k to only MAIL:RCPT months ago 
because too many servers like gmail round robin their connections.

-Mike Elliott
Msen Sysadmin

> 
> -- 
> Anthony C Howe                                 +33 6 11 89 73 78
> http://www.snert.com/       ICQ:
7116561         AIM: Sir Wumpus
> 
> "held in my arms / his sun washed face / eyes closed" - Anthony

Lists Index Date Thread Search