CustomFunction: WhiteListFutureSender

William Burns William.Burns at AEROFLEX.COM
Mon Nov 22 22:55:20 GMT 2004


This is very cool.
I've got a similar scheme on one of my mail servers (That's not running
I refer to this as an AutoWhitelist.

paddy wrote:

>The idea is to whitelist recipients of outgoing mail from known
>(client) relays, for return mail.  When such an outgoing mail is
>detected the value "<sender_ip>,<recipient>" is stored as the key in
>a tied hash along with a value that can be increased by subsequent
>hits, and aged by a cron job.
Have you created something to filter mail based on your database? I
don't understand how the sender_ip is used.

The mail that you trigger on is the outgoing mail, right?
In that case the sender IP is going to be the address of one of your
end-user PCs. Or... The IP address of a mail server if you're running
this on a mail gateway?

In case you're interested...
In my system (a kludge) I keep a separate database (a.k.a. text file)
for each of my users. Each database contains a list of addresses to
which that user sent mail. (There are two databases per user actually,
the other one contains domains that the user manually chose to whitelist)
When inbound mail is being delivered to a local mailbox, there's a
procmail script that checks the user's databases for the sender's
address. Any mail from a username not listed in the per-user whitelist
databases gets tagged w/ "[Unknown User]" in the subjectline.

>Praise, questions, comments, corrections, flames, whatever, all welcome.


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