While testing the folder_by_date feature in 2.1.8 , I've noticed that it is using the date from the Date: header.
This means that if anyone who sent to the list has their clock off, and sent a message with an incorrect date, the message will not be saved to the correct place. (In one case, someone's clock set to 1980 caused a whole new directory to be created).
This should probably use one of the system-supplied date headers instead, which would (most likely) indicate that actual time it was received by the archiving system. The very first line of an mbox format would probably be an easy place to take it from - ie:
>From list_at_list.com Sun Jun 1 06:39:39 2003
-Chris
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