Maintaining a whitelist

Vernon Schryver
Thu Jul 19 15:46:10 UTC 2001

> From: Gustav Foseid <>

> I have a problem maintaining a whitelist...
> My DCC server is collecting checksums from a server acting as an UUCP relay
> (no, UUCP is not dead). A few hundred domains have their MX pointing to the
> UUCP server and download their mail with UUCP. This adds up to many
> thousand users.
> Maintaining a list of mailing lists these people are subscribing to is an
> impossible task. Most mailing lists are very unlikely to have many
> recipients here, but I am more concerned with auto responders off all
> kinds.
> I am interested in other peoples experiences with building whitelists.

I think avoiding false positives is more important than preventing
false nagatives.  It is better to pass spam than to reject legitimate
mail.  There are at least two ways to do that with the DCC:

  1. only insert the headers and let end users do any rejecting using
    procmail or other tools.

  2. use the To: whitelist mechanism in dccm.  Mail sent to white-listed
    targets is passed regardless of the DCC counts.  Perhaps use `dccm -W`
    and "OK2" entries to cause only addresses explicitly listed to be
    affected.  (sheesh!--who wrote and proofread the description of -W?)

Perhaps I need to change how dccm treates mail addressed simultaneously
to white-listed and unlisted addressees.  Currently, the message
is rejected, discarded, or delivered to all addressees.  I've resisted
doing this, because it requires that dccm record the addressees at
the start of the SMTP transaction and at the end remove those who should
not receive the message.  It is also not clear what SMTP reply status
I should generate for a message that is partly delivered.
What do you think?

Vernon Schryver

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