Re: Dangers of discarding duplicated messages
From: Gene Rackow (rackow_at_mcs.anl.gov)
To: Maciej Soltysiak <email@example.com> Date: Fri, 18 Feb 2005 16:57:55 -0600
There are lots of other things that may need to be done to handle
dealing with duplicated message-id's as well. Note that the RFC's
mandate that the message-id is unique per message.
A number of IMAP packages use the message-id as a way of keeping
track of the message in the various folders.
Having messages with the message-id breaks the standards, may
cause problems in message handling, etc.
The problem is bigger than just the anti-spam packages out there.
From the original message it was indicated that these many dups
might be picked up by the AV/AS software on the server. If it is,
the blocking of the message should happen before the message-id
gets entered into the users cache of delivered messages. Therefore
the 1st non-spam message should still be able to get through to the
Maciej Soltysiak made the following keystrokes:
>Thursday, February 17, 2005, 7:57:01 PM, you wrote:
>> It seems to be required that programs that automatically discard
>> duplicate messages have to use a checksum over the body and part of the
>> header of the emails instead of relying on the message ID.
>Very interesting indeed Adrian.
>So to sum it all up just for now, the advisories are two.
>One for users, one for developers of MUAs.
>Users: Beware of the fact that automatic discarding of duplicated messages
> may result in you not getting the original mail in case someone exploi
> the effect Adrian depicted.
>Developers: Consider using checksum of the email messages, not only the
> Message-ID to distinguish between duplicated messages.
>Am I correct?
>Fortunately I was never using this MUA feature - I just take care of the
>duppies manually, which is not a big chore for me I must say.